NR22 – Occupational Health and Safety in Mining

22.1 – Aims
22.2 – Scope of Application
22.3 – Mining Company and Hand Mining Permit Holder Responsibilities
22.4 – Workers’ Responsibilities
22.5 – Workers’ Rights
22.6 – Work Site Organization
22.7 – Circulation and Transport of Personnel and Materials
22.8 – Continuous Belt Conveyors
22.9 – Work Sites
22.10 – Ladders
22.11 – Machinery, Equipment, Tools and Installations
22.12 – Lifting Equipment
22.13 – Wire Ropes, Chains and Sheaves
22.14 – Rock Stability
22.15 – Underground Openings
22.16 – Handling and Lining of Underground Openings
22.17 – Dust Suppression and Control
22.18 – Communication Systems
22.19 – Sign-posting Work Sites and Traffic Corridors
22.20 – Electrical Installations
22.21 – Use of Explosives and Accessories
22.22 – Floating Dredge Operations
22.23 – Hydraulic Mining
22.24 – Underground Ventilation
22.25 – Ore Dressing and Treatment
22.26 – Waste, Tailings and Product Disposal
22.27 – Lighting
22.28 – Fire-fighting and Explosion Prevention
22.29 – Inflammable Dust Explosion Prevention in Underground Coal Mines
22.30 – Flood Prevention
22.31 – Radioactive Equipment
22.32 – Emergency Operations
22.33 – Emergency Exits and Escape Routes
22.34 – Mine Shutdowns and Restarting Operations
22.35 – Information, Qualification and Training
22.36 – Internal Committee for Accident Prevention in Mining – CIPAMIN
22.37 – General Matters

22.1 – Aims
22.1.1 – This Regulating Standard is drawn up for the purpose of determining the rules to be followed in organizing the work and the work site, in order to help in making compatible the planning and development functions in mining, in the constant pursuit of worker safety and occupational health.

22.2 – Scope of Application
22.2.1 – This rule applies to:
a) underground mining;
b) open cast mining;
c) hand mining;
d) ore dressing and treatment;
e) mineral exploration.

22.3 – Mining Company and Hand Mining Permit Holder Responsibilities

22.3.1 – It is the responsibility of the mining company, the hand mining permit holder and the mine manager to ensure strict compliance to these rules, reporting information to the inspectors when required. – The mining company, the hand mining permit holder or the mine manager, must inform the inspecting entities of the names of those responsible for each sector.

22.3.2 – When work is undertaken through contractors by the mining company or by the hand mining permit holder, the contract must indicate the name of the person responsible for compliance to this Regulatory Standard (NR22). (Amended by Ordinance SIT No.27, October 1, 2002)

22.3.3 – A suitably qualified engineer must supervise every mine and other activity referred to under item 22.2. – The mining company or the hand mining permit holder must record the technical supervisions carried out by the legally qualified professional, as well as observations and interventions proposed and realized, by means of a register or personal files. These records shall be kept at the establishment at the disposal of the supervisory bodies. (Inserted by Ordinance MTE No.732, May 22, 2002)

22.3.4 – The mining company and the hand mining permit holder must also:
a) – discontinue any activity which may subject the workmen to conditions of imminent
and serious risk to their health and safety;
b) – discontinue duties, when proposed by the workmen, as a result of possible serious
and imminent risk, when confirmed by their immediate superior, who must take the necessary action and
c) – supply contractors with full information regarding potential risks in the areas in which their work is to be undertaken.

22.3.5 – The mining company or the hand mining permit holder will co-ordinate the implementation of the measures relative to contractor’s employee safety and health and supply the means and conditions by which compliance of this rule is achieved.

22.3.6 – The mining company and the hand mining permit holder will prepare and implement a Program for Medical and Occupational Health Control – PCMSO, according to NR7.

22.3.7 – The mining company and the hand mining permit holder will prepare and implement a Risk Management Program – PGR, covering all aspects of this rule, including at least the following:
a) physical, chemical and biological risks;
b) explosive atmospheres;
c) oxygen deficiencies;
d) ventilation;
e) respiratory protection, in accordance with Normative Instruction Nº 1, dated 11/04/94, issued by the Safety and Occupational Health Secretariat;
f) work accident investigations and evaluations;
g) work ergonomics and organization;
h) risks arising from undertaking work at height, at depth or in confined spaces;
i) risks arising from the use of electricity, machinery, equipment, vehicles and manual labour;
j) individual protective equipment of compulsory use, with at least the conditions called for under NR6;
k) rock stability;
l) emergency plan, and
m) others resulting from the introduction of new technology. – The Risk Management Program – PGR must include the following:
a) anticipate and identify risk factors, taking into account the information supplied by the Risk Manual prepared by CIPAMIN:
b) evaluate risk factors and workers exposure;
c) establish priorities, objectives and chronograms;
d) follow up implemented control measures;
e) monitor risk factor exposure;
f) record and maintain collected data for at least twenty years, and
g) evaluate program at least once a year, contemplating the evolution of the schedule, with record of implemented and planned control measures. (Inserted by Ordinance MTE No.732, May 22, 2002) – The Risk Management Program, its amendments and complementary inclusions, must be presented to and discussed with CIPAMIN, for follow up of control measures. – The Risk Management Program should include the above mentioned action levels, adopting them as preventive measures in order to minimize the probability of exceeding occupational exposure limits, and also implementing measures for periodic monitoring of the exposure, informing the workers and the medical controls, considering the following definitions: (Amended by Ordinance SIT No.27, October 1, 2002)

a) occupational exposure limits are tolerance limits given in NR15 or, in the absence of these, the occupational exposure limits adopted by the American Conference of Governmental Industrial Hygienists – ACGIH, or the figures which may be determined by collective negotiation, provided that they are more stringent than the former; (Amended by Ordinance SIT No.27, October 1, 2002)

b) levels of action for chemical agents are the environmental concentration figures equal to half the exposure limits, as defined in line “a” above, and

c) levels of action to be taken in the case of noise are the figures equal to 0.5 (over 50%), according to the criteria determined by NR15, Annex I, item 6.

22.4 – Workers’ Responsibilities
22.4.1 – The workers should:

a) zealously care for their own safety and health or that of others who may be affected by their actions or neglect at work, always co-operating with the mining company and the hand mining permit holder, to comply with legal rules and regulations, including company safety and health rulings, and

b) instantly inform their immediate supervisor of all situations that would appear to offer risks to their own safety and health, or that of others.

22.5 – Workers’ Rights
22.5.1 – The rights of the workmen are:

a) to interrupt their duties whenever there is evidence that serious and imminent risks are offered to their own safety and health or that of others, reporting this to their supervisor who will take adequate measures, and

b) to be informed of the existing risks to their safety and health, at their place of work.

22.6 – Work site organization
22.6.1 – The company or the hand mining permit holder will adopt all necessary measures to ensure that:

a) the work places should be designed, built, equipped, used and maintained in such a way that the risks to the workers’ safety and health are eliminated or reduced to a minimum which is both practicable and feasible, thus enabling them to undertake the duties entrusted to them;

b) that the work stations be designed and installed in a manner following ergonomic principles.

22.6.2 – Operational mining sites must have duly identified entrances showing the name of the mining company or that of the hand mining permit holder, whilst access roads must also be duly sign-posted.

22.6.3 – Miners may not be unaccompanied under the following working conditions:

a) underground when undertaking:

I) hand removal of unstable blocks of rock;
II) containment of dislocated rock mass;
III) hand drilling;
IV) restarting work in a “cul-de-sac” of over 10m length, and
V) charging, detonating and misfire removal.

b) in open cast mining, when charging, detonating or removing misfired charges. – The mining company or the hand mining permit holder must implement safety rules for the supervision and control of the other sites, where unaccompanied work is allowed.

22.7 – Circulation and Transport of Personnel and Materials
22.7.1 – Every mine must have traffic rules which determine right-of-way, minimum distances to be held between machinery, equipment and vehicles, and the speeds allowed for safe operations under the conditions offered by the road surfaces.

22.7.2 – Load or personnel carriers must be fitted with immobilizing devices to avoid use by unauthorized personnel.

22.7.3 – Tire-mounted load haulers or personnel carriers must be fitted with headlamps, running lights and a reverse sound warning coupled to gear box operation; also a horn and warning signal to indicate change of direction and reversing mirrors.

22.7.4 – The capacity and maximum speed permitted for the operation of transport carriers should be placed in a position visible to all.

22.7.5 – Locomotives and other means of transport may only be driven by qualified, authorized and duly identified personnel.

22.7.6 – Transport in open cast mines must obey the following minimum requisites:

a) the outer limits of the mine benches used as roads must duly marked and signalled, making them fully visible both by day as well as by night;

b) the width of mine roads must be twice the width of the largest vehicle in use, in the case of a single-track road, and three times in the case of two-way traffic.

c) the sides of the mine benches or roads, where the risk exists of vehicles falling off, furrows should be built having a minimum height equal to half the largest tire diameter in use. – When the mining plan and the nature of the work or the size of the mine makes it impossible to comply with line “b” above, the width of the traffic lanes can be at least one and a half times greater than the width of the largest vehicle used, and there must be interspersed parking stalls for the vehicles, as well as additional procedures and sign-posting used to guarantee traffic safety shall be adopted as provided for in the Traffic Plan. (Amended by Ordinance MTE No.1894, December 9, 2013)

22.7.7 – Small-size vehicles operating in an open cast mining area shall be fitted with a telescopic mast with flag attached, and also use a signaling flag and keep on headlights, even during the day, so that they are more easily seen by operators of other equipments and vehicles. (Amended by Ordinance SIT No.27, October 1, 2002) – Vehicle lighting must be used in conditions of poor visibility and at night.

22.7.8 – Unpaved mine roads must be humidified in order to minimize the dust generation. (Amended by Ordinance MTE No.1894, December 9, 2013)

22.7.9 – When only a single-track road is available for the circulation of personnel and material transport or vehicle traffic underground, the tunnel section must be at least 1.50m wider than the width of the largest vehicle using it. Special traffic rules must also be implemented. – When the mining plan and nature of the work is such that the safe distances mentioned in this item cannot be adopted, openings must be made in the walls of drives or inclines having at least 0.60m depth x 2.00m height x 1.50m length, duly sign-posted and unobstructed at every 50m, to be used as personnel shelters.

22.7.10 – When using winches or mine cars for hauling supplies through inclines on which the roadway is not separated from pedestrian traffic by a suitable barrier, this equipment must be halted until pedestrian traffic ceases.

22.7.11 – For passenger transport throughout the mine, adequately designed personnel carriers must be used, having the following minimum requisites:

a) safe operating conditions;
b) fitted with seats with a back-rest;
c) fitted with safety belts;
d) fitted with a covering for weather-protection or accidental contact with the tunnel roof;
e) boarding and landing ladders, when necessary. – In situations where a safety belt could afford additional risks, its use will be dispensed with, although all other safety rules are to be observed. – The mining company or the hand mining permit holder bears co-responsibility for the safe transport of workmen when an outside service contractor used for this purpose.

22.7.12 – The joint transport of personnel and supplies such as tools, equipment and raw materials, is only allowed when the quantities are compatible with safety requisites and the supplies are packed or conditioned in a suitable manner, placed in an adequate compartment, duly closed and secured so as to avoid causing injury to the workmen.

22.7.13 – The carrying of passengers by mine machinery or equipment can only be allowed if they have been duly designed or adapted for use as personnel carriers, and are driven by a suitably qualified operator.

22.7.14 – The vertical transport of passengers is only allowed in cabins or cages with the following features:

a) a minimum height of 2m;
b) doors having cross-bars to avoid accidental opening;
c) cross-bars to remain shut whilst in motion;
d) sturdy roof and fitted with hand-railings and emergency exit;
e) side protection avoiding accidental access to the outside;
f) lighting;
g) well protected access;
h) distance of less than 0,15m between the loading platform and the cage;
i) the maximum load capacity of the cage and its velocity will be shown in a visible position;
j) a system of communication with the hoist operator will be available at the loading and unloading stations. – Passenger transport during the shaft sinking and equipping stages will be in accordance with the following minimum requirements:

a) the shaft will be fitted with a tilt-opening safety door to avoid that passengers or supplies may fall and the door is to remain shut whilst there are people within the shaft;
b) the shaft collar is to be concreted;
c) the vertical transport conveyance (bucket) must be made of good quality material, good load resistance and a lateral height of at least 1.20m;
d) the maximum cage velocity of 1.20 m/s should be reduced when approaching the shaft bottom;
e) a sound signaling device should be available, as specified in item 22.18;
f) the joint transport of passengers and materials is prohibited.

22.7.15 – Means of conveyance and passenger transport in ramps or inclines fitted with tracks, must obey the following minimum requisites:

a) available seating capacity for the maximum number of users;
b) front and overhead protection to avoid accidental contact with the roof;
c) the maximum load capacity, the maximum passenger capacity and the velocity of the conveyance, must be shown in a visible position;
d) passengers may only enter or exit the conveyance at the appropriate places. – Passenger traffic during the sinking and equipping stages of tracked ramps or inclines will obey the following minimum requirements:

a) a maximum speed of 1.20 m/s which must be reduced when approaching the bottom of the ramp or incline;
b) the conveyance must be fitted with a foot-board for support of the passengers;
c) the conveyance must be fitted with sound signaling device, as specified in item 22.18;
d) passengers and supplies may not be carried jointly.

22.7.16 – When carrying passengers on inclines or shafts, the hoist operator must be informed by use of the signaling system.

22.7.17 – Should a risk situation arise in the transport by cage or incline, hoist operation should stop immediately so that the proper measures may be taken to reinstate transport safety.

22.7.18 – Foot traffic areas must be duly sign-posted, kept unimpeded and protected against falling objects; they must also be maintained in good safety and traffic conditions.

22.7.19 – When the distances covered by a miner on foot, to reach or return from his workplace, add up to more than 2,000m., the mine must supply a mechanized means of transport for this purpose.

22.7.20 – In underground horizons or inclines with two-way traffic, sidings should be made available at regular intervals, or the mine should have signaling devices to indicate the right-of-way, to avoid the occurrence of simultaneous traffic in opposite directions.

22.7.21 – The transport of supplies in hand drawn mine cars is prohibited. – The manual shunting of mine cars over a distance of not more than 50m and at a gradient of less than 0.5% is allowed, when the strength exerted by the miner does not compromise his health and safety in any way.

22.7.22 – Every mine car to be moved on inclines must be connected to a main coupling system and a secondary safety system.

22.7.23 – The mine car convoy can only be put into motion when all cars are coupled together.

22.7.24 – Manipulation of coupling devices when mine cars are moving is disallowed, except when designed for this purpose.

22.7.25 – Mine cars must be fitted with a limiting device, which holds the distance between cars to a minimum of 0.50m.

22.7.26 – Where mine car coupling and uncoupling takes place, safety measures should be adopted regarding cleanliness, lighting and free space for circulation of people.

22.7.27 – Mine car tipping stations should be fitted with:
a) fall protection both individual and collective;
b) protective devices that allow working over the screens if necessary;
c) lighting
d) adequate signs;
e) devices and work procedures that reduce the risk of dust exposure for the workmen;
f) braking devices, which avoid unforeseen movement when, hand tipping.

22.8 – Continuous belt conveyors
22.8.1 – In design, projects, installation, assembly and operation of continuous belt conveyors, the control measures specified in the risk analysis contained in the Risk Management Program provided for in sub-item 22.3.7 and the specifications of the applicable ABNT technical standards, especially NBR 6177, NBR 13742 and NBR 13862 shall be observed, without prejudice to other requirements of this standard. (Amended by Ordinance SIT No.202, January 26, 2011) The continuous belt conveyors already in use and which were built prior to the effectiveness of sub-item 22.8.1 shall have control measures to mitigate the risks identified in the evaluation phase of the Risk Management Program. (Inserted by Ordinance SIT No.202, January 26, 2011)

22.8.2 – The design and building of continuous belt conveyors should consider tensioning the system, so as to assure adequate tension for operational safety, as specified in the project.

22.8.3 – The installation of disconnecting mechanisms is obligatory over the full length of the continuous belt conveyors, especially where the access of workmen is routine. – The continuous belt conveyor system should be fitted with a safety mechanism which stops their operation when safety limits are attained, as specified in the project, and should at least include the following situations:
a) belt breakage;
b) excessive belt slippage over rollers;
c) excessive belt nonalignment;
d) belt overload;

22.8.4 – Walkways fitted with hand-railings and foot-boards must be used for crossing the conveyor system.

22.8.5 – Traffic is allowed below the conveyor belt system only where suitable protection exists against falling tools or supplies.

22.8.6 – The conveyor belt system start-up will only take place after 20 seconds from an audible alarm or other method of communication, indicating that this is to take place.

22.8.7 – Continuous belt conveyors having the loading side higher than 2m from the ground, must have walk-ways over their full length, fitted with hand-railings and foot-boards duly closed off, with a height of at least 0,20m. – Belt conveyors which due to the nature of their operation cannot withstand the weight of a walk-way structure, should be fitted with a safety procedure system for inspection and maintenance work.

22.8.8 – Safety fencing or other devices, which avoid accidental contact, should protect all transmission rollers or angle stations.

22.8.9 – Where there is the risk of falling objects or the uncontrolled dropping of ore, continuous belt conveyor systems operating at a height, must be fitted with protective devices.

22.8.10 – Cleaning and maintenance of continuous belt conveyors can only be undertaken when the system is shutdown and stationary, except where water jets or other such method are used, which then require special safety features which do not allow the workmen accidentally to touch moving parts.

22.9 – Work Sites
22.9.1 – Work stations must be fitted with moving platforms, whenever the height of the work station is more than 2m or the shape of the ground below does not guarantee the necessary safety requirements. – The moving platforms must be fitted with anti-skid walking surfaces of at least 1m width, with foot-boards 0.20m high and guardrails.

22.9.2 – Machinery and equipment must not be used as work platforms, if not designed, built or safely adapted for this purpose, and only after their use has been authorized by a competent safety engineer.

22.9.3 – The overhead walkways and their accesses must be fitted with guardrails and foot-boards 0.20m high, once their safety and conditions of use have been guaranteed. – The walkway surfaces must be anti-skid, wear-resistant and kept in safe conditions of use.

22.9.4 – The working walkways must be at least 0.60m wide, when used occasionally, and 0.80m wide in other cases. – The working walkways built and in use that were not designed and erected in accordance with the requirements made in this item, must have special working procedures to ensure safe operation.

22.9.5 – Walkways having an inclination of more than 15º and a height of over 2m, must be fitted with foot-boards of 0.20m and screened guard-rails up to a height of 0.40m above the foot-board, over its full length, or some such system to prevent the users from falling.

22.9.6 – Work on waste heaps and ore dumps and in the clearing of tunnels or drives, must be undertaken with careful observance of the special safety regulations implemented by the mining company or hand mining permit holder.

22.9.7 – Work on roofs may only be undertaken when using “parachute” type safety belts fixed to a guide rope or some such similar method to avoid falls.

22.9.8 – When working on inclined surfaces, with the risk of falls of more than 2m., the use of a suitably anchored safety belt is compulsory.

22.9.9 – Mining levels and working surfaces should be suitably drained.

22.10 – Ladders
22.10.1 – Walkways fitted with guardrails and foot-boards must be installed for crossing shafts, chimneys or any opening in the ground.

22.10.2 – When the access to work sites has an inclination of more than 20º and less than 50º with the horizontal, a system of securely fixed ladders shall be installed, with the following features: (Amended by Ordinance MTE No.1894, December 9, 2013)

a) steps and flights which are duly uniform;
b) when steps are 0.18m to 0.20m apart, risers must be fitted;
c) the vertical distance between landings or flights cannot be more than 3.60m;
d) sturdy guardrails of between 0.90m and 1.00m must be fitted; and
e) the floor must be made of non-slip material

22.10.3 – When work site accesses have an inclination of more than 50º with the horizontal, a hand ladder should be made available, having the following requisites:

a) sturdily built and secured in a safe manner, to avoid the risk of falls;
b) free of broken or loose rungs;
c) the distance between steps should be 0.25m to 0.30m;
d) there should be a minimum spacing of 0.10m between the step and the wall face or other obstruction behind the ladder, allowing the feet to be firmly placed;
e) rest landings must be installed having at least 0.60m width by 1.20m length, at intervals of at most 7.00m, wide enough to allow workmen to pass each other;
f) overlap the rest landing by at least 1.00m. – Should the ladder be installed in a shaft which is a passageway, it should be built in consecutive flights each with a different axis and at least 0.60m apart. – Should the ladder have an inclination of more than 70º with the horizontal plane, it should be fitted with a protective cage starting at 2.00m from the ground, or some such similar device to avoid the risk of falls.

22.10.4 – Wooden ladders should at least have the following characteristics:

a) the wood should be of good quality, free of knots or cracks that could compromise its resistance;
b) the wood should not be painted or treated in any way to avoid hiding imperfections;
c) the distance between each rung should be between 0.25m and 0.30m;
d) spacing of at least 0.10m should exist between the rungs and the wall or any other obstruction behind the ladder, allowing the users feet to be firmly placed;
e) if there is no hand railing at the top of the ladder, it should protrude by at least 1.00m above the ground or opening.

22.10.5 – In the case of metallic ladders, additional safety measures should be adopted when close to electrical installations.

22.10.6 – The use of chain ladders is only allowed in the shaft-sinking stage of underground mines.

22.11 – Machinery, equipment, tools and installations
22.11.1 – All machinery, equipment and auxiliary/electrical installations, must be designed, erected, operated and maintained in conformity with existing technical standards and the makers’ instructions, all duly supervised by qualified technicians.

22.11.2 – The machinery and equipment must be fitted with starting and stopping devices installed in such a way that:

a) the starting and stopping operations can be undertaken by the operator at his work station;
b) these start/stop switches are not located in a dangerous position on the machine or equipment and will not be the cause of additional risks;
c) the start/stop switch may in an emergency, be operated by any person other than the operator;
d) the start/stop switch cannot be accidentally used by the operator or accidentally operated in any way or form:

22.11.3 – All machinery, equipment, systems and other facilities that operate automatically, must be fitted with easily accessible mechanisms that stop them when required.

22.11.4 – Machinery and automatically controlled systems once shutdown, can only be re-started after a sound warning alarm has been operated.

22.11.5 – Large-size machinery and equipment must be fitted with a sound alarm to indicate start of operations or a change in direction. – All large-size machinery and equipment capable of reversing, must be fitted with a sound alarm to indicate that this maneuver is about to begin. – All machinery and equipment operating in an isolated marked-off area, need not have a sound alarm.

22.11.6 – All machinery and equipment operating where there is a risk of falling objects and supplies, must have adequate operator protection. – All machinery and equipment must have adequate operator weather protection.

22.11.7 – All internal combustion engines underground can only be diesel driven and the following conditions must be observed:

a) wherever they operate, an efficient ventilating system must be in place;
b) a quality air filter should be fitted to the motor, with a cooling and washing system for the exhaust gases or a catalyser;
c) the motor should be fitted with a system to prevent flames and sparks from leaving the engine exhaust in mines having explosive gas emanations or when transporting explosives;
d) periodic sampling of the air should be undertaken, at intervals not exceeding one month, at the most representative spots in the area affected, also the engine exhaust gases at intervals which do not exceed 3 months, under full load and tick-over conditions, sampling at least nitrous gases, carbon monoxide and sulfur dioxide.

22.11.8 – When starting holes with pneumatic rock drills, a special securing device must be used to hold the drill steel, avoiding the use of the hands.

22.11.9 – Machinery and equipment which run the risk of toppling over, breaking certain accessories or throwing off materials and parts, must be fitted with proper safety protection for the operator.

22.11.10 – It is compulsory that all machinery / equipment moving parts within reach of workmen and which may be the cause of risks to them, must be duly protected; – When protective screens or others are removed for maintenance or testing purposes, the nearby areas should be roped off, until they are replaced and the equipment set in motion once again.

22.11.11 – The installations, machinery and equipments in locations with the possibility of explosive atmospheres shall be explosion-proof, observing the specifications appearing in the Brazilian Technical Standards Association – ABNT, NBR 5418 – Electrical Installations in Explosive Atmospheres and NBR 9518 – Electrical Equipment for Explosive Atmospheres – General Requirements. (Amended by Ordinance SIT No.27, October 1, 2002)

22.11.12 – Maintenance and fueling of vehicles and equipment should be undertaken by a trained workman, using methods and devices which guarantee operating safety.

22.11.13 – All transport vehicles and equipment must be duly registered at the mine establishment, and these records must contain the following:

a) their technical features;
b) the periodicity and result of inspection and maintenance procedures;
c) accidents and other abnormalities;
d) corrective measures adopted or to be adopted;
e) name of employee or firm who carried out the inspection or maintenance procedure. – The mentioned record must be held for at least a year at the disposal of the authorities.

22.11.14 – Tools must be appropriate for the use to which they are put, whilst using defective, damaged or inadequately improvised tools is not allowed.

22.11.15 – Air hoses and fittings supplying pneumatic equipment should have the following characteristics:

a) these must remain protected and firmly secured to the inlet and outlet tubes, preferably, well away from circulation areas;
b) these must be fitted with an auxiliary device, which guarantees the containment of the hose, avoiding the whipping action of the hose in case of accidental detachment. (Amended by Ordinance SIT No.27, October 1, 2002)

22.11.16 – Compressed air hoses should be placed in such a way as to avoid accidental impacts.

22.11.17 – When using and handling gunpowder-fired fixing tools, the following conditions must be observed:

a) the operator must be duly qualified and authorized;
b) the operator must make sure that other personnel are not within range of the tool, even though behind walls;
c) the operator must ascertain that no inflammables or explosives can be found at the site where operations are to take place;
d) the fixing tools are to be transported and saved unloaded minus the firing pin and hammer;
e) the tools are to be saved in a place to which access is restricted.

22.11.18 – All manual electrical tools or equipment must have double insulation, except when battery-operated.

22.11.19 – When operating heavy machinery and equipment, the following safety rules must be observed:

a) isolate and sign-post the area, access to which can only be authorized by the operator or person responsible;
b) before start-up and operation, the heavy equipment operator must ensure that there is nobody below or in a position of danger;
c) do not operate heavy equipment where its stability could be compromised;
d) take special precautions when operating close to power lines. – Heavy machinery and equipment must at least be fitted with the following:

a) indication of its maximum capacity fully visible on its structure or chassis;
b) a comfortable seat fixed in such a way as to reduce the effect of vibration.

22.11.20 – Maintenance procedures, inspections and repairs of any kind, cannot take place on machinery or equipment upheld only by hydraulic systems.

22.11.21 – When mounting or disassembling pneumatic tires, the following safety conditions must be observed:

a) the pneumatic tyre must be completely emptied, and the valve core removed before disassembly, shaft removal or repairs take place, when the tyre need not be taken off the wheel;
b) filling pneumatic tires can only be done within a special enclosure, until sufficient pressure is reached to force the tyre over the wheel rim creating a pneumatic seal;
c) the special enclosure mentioned in line “b”, must be able to withstand the impact of a wheel and tyre containing 150% of the maximum specified air pressure.

22.11.22 – The choice of the steel rods used for releasing loose rock in the hanging-wall, must consider the safety of the work and the ergonomics. The rods should be the right length and resistance, but must also be as light as possible to avoid excessive muscular stress.

22.11.23 – Compressed air cylinders must be stored in well-ventilated warehouses, fully protected against falls, heat and accidental impacts. They must also comply with the standards of NBR 12791 – Seamless steel cylinder for high pressure gases storage and transportation, and NBR 11725 – Compressed gas cylinder valve outlet and inlet connections, and follow the manufacturer’s recommendations. (Amended by Ordinance SIT No.27, October 1, 2002)

22.11.24 – Every endless rope can only be used under the following conditions:

a) to be fitted with an anti-backlash device to prevent the rope from continuing its movement when the machine is disconnected;
b) to be fitted with a device which protects moving parts at the actuator and inversion stations;
c) to be installed in such a way that the actuating mechanism cannot have sudden or uncontrolled motion;
d) to ensure that it can only be started after 20 seconds following an audible warning or other such system of communication.

22.12 – Lifting Equipment
22.12.1 – All lifting gear must be fitted with the following:

a) an indication of the maximum load and maximum speed must be given and the lifting gear must be fitted with a mechanism to ensure a shutdown should these limits be attained;
b) every machine of more than 40 kW must be fitted with a speed indicator and speed limiting device;
c) for underground operation a depth indicator must be installed, operating independently of the drum;
d) safety brake;
e) emergency brake when used for personnel transport;

22.12.2 – Hoisting shafts must be equipped with at least the following installations and devices:

a) barriers that avoid accidental access to the shaft;
b) gates for access to the cabin and cage on each level;
c) automatic cut-off devices which stop the electric current reaching the hoist in the case of the cabin or cage exceeding its speed and positioning, either when going up or down;
d) a mechanical or automatic alarm signal to be fitted at every shaft level;
e) an integral telephone system enabling all main shaft levels to communicate with the hoist and the surface;
f) a sound / light alarm system or a radio / telephone system, allowing communication throughout the shaft for use in repair work or emergencies.

22.12.3 – Production and man-hoists must be fitted with a braking system capable of holding the conveyance in any position, when carrying at least 150% of its maximum full load capacity. – The vertical haulage braking system will be used when:

a) a stop signal is given;
b) the haulage system is inoperative;
c) protection devices have been actuated;
d) a power cut has occurred;
e) the speed limit has been overreached;
f) the maximum load capacity has been exceeded. – The braking system can only free the hoist when the motors have been started.

22.12.4 – Mine hoists must be erected according to existing standards and technical specifications and to the maker’s instructions. – If fixed boom lifting equipments are used, the minimum requirements set out in Annex III of this Standard (NR22) must be met. (Amended by Ordinance MTE No.1894, December 9, 2013)

22.13 – Wire ropes, chains and sheaves
22.13.1 – The cables, chains and other means of suspension or traction, and their respective connections, shall be designed, specified, installed and maintained in shafts and inclined planes, according to the manufacturers’ instructions and to the specifications in NBR 6327 – Steel Cable for General Purposes – Specifications, NBR 11900 – Steel Cable Ties Ends – Specifications, NBR 13541 – Load Handling – Steel Cable Tie – Specifications, NBR 13542 – Load Handling – Load Ring, NBR 13543 – Load Handling – Steel Cable Tie – Use and Inspection, NBR 13511 – Load Handling – Thimble for Steel Cable, NBR 13545 – Load Handling – Shackles. They must also have been previously certified by an entity duly accredited by the National Institute of Metrology, Normalization and Industrial Quality-INMETRO, or by an international certification body. (Amended by Ordinance SIT No.27, October 1, 2002)

22.13.2 – The ropes, chains and other means of support or traction must follow the requisites given below:

a) within the shaft, these items must have a safety coefficient of at least 8 in relation to the maximum static load;
b) other mine transport systems which may cause personal injury in the case of an accident, must have a safety coefficient of at least 6 in relation to the maximum static load;
c) when lifting vehicles or their separate parts, a resistance of at least 10 times the maximum load is required; – By technical justification, the safety and strength coefficients mentioned in this item may be altered, under the responsibility of a legally qualified professional technician. – Every six months at least, a survey must be made to ascertain the positioning of the rope sheave pulleys, according to the technical features of the respective design.

22.13.3 – The mining company or the hand mining permit holder will enter in a log book or other similar recording system, with full technical responsibility, the following data relative to the ropes, chains and other support or traction items, used in the hoisting activities:

a) composition and nature;
b) mechanical features;
c) name and address of supplier and manufacturer;
d) type of tests and inspections recommended by the maker;
e) type and result of the inspections undertaken;
f) date and installation of the repairs and part replacements;
g) nature and consequences of eventual accidents;
h) load capacity conveyed;
i) dates of inspections with inspectors’ names and signatures. – The records mentioned in this item must be kept for at least one year, at the disposal of the authorities.

22.13.4 – When using a friction rope sheave, all mine shaft levels are to be indicated on it and on the depth indicator panel, corrected concurrently with every rope adjustment.

22.14 – Rock stability
22.14.1 – All mining work underground and at surface is to be surveyed and duly recorded on maps and blueprints, to be duly revised and updated periodically by qualified professional. – Every six months at least topographical surveys must be made to check the position of shaft headgear.

22.14.2 – The mining company or the hand mining permit holder must adopt procedures to control rock stability, using rock mechanics engineering criteria, which include the following::

a) monitor stratum movements;
b) the hanging wall and foot wall in work sites and where personnel circulate, must receive special attention by mine staff;
c) monitor and control the benches and slopes in open cast mines;
d) check the impact formerly mined areas may be having on rock stability;
e) check the presence of other factors on rock stability, especially water, gases, altered rock, faults and cracks.

22.14.3 – The mining method in which a controlled subsidence of the rock massif takes place or when using the room and pillar method, should both be accompanied by safety measures to allow permanent monitoring of the mining process and supervision by qualified personnel.

22.14.4 – When situations of potential instability are encountered through evaluations which consider local geo-technical and geo-mechanical conditions, mining work should immediately be halted, the workers withdrawn from the risk areas and the necessary corrective measures initiated. This work is to be undertaken by suitably qualified personnel under effective supervision. – The following occurrences are an indication of potentially unstable rock conditions:

a) in open cast mines:

I – main ore body fractures or loose blocks on the pit bench face and cracks at the top of the bench;
II – water trickling from rock fractures;
III – the appearance of surface subsidence;
IV – negative slope structures;
V – water percolation through fractures or mechanical breakages.

b) in underground mines:

I – mechanical breakages with loose blocks on hanging and foot walls;
II – breakages in the hanging wall, in the bedrock or in the pillars;
III – abnormal quantities of water appearing during excavation, drilling, or after blasting;
IV – significant deformation to sustaining structures. – When the situations described in sub-item occur, without due monitoring having taken place, as recommended in sub-item 22.14.2, work must stop immediately and the necessary corrective measures should be implemented. – Mining operations should only start again after corrective measures have been taken and the sector has been formally freed by those responsible.

22.14.5 – The disposal of any material close to the crest of the benches and the parking of mining equipment should follow safety regulations governing minimum distances, determined by the stability and height of the bench.

22.14.6 – Material at risk from falling from the crest of upper benches, must be stabilized or removed to an adequate distance.

22.15 – Underground openings
22.15.1 – Underground drives or tunnels must be opened and maintained safely throughout their useful life.

22.15.2 – Shaft collars and mine accesses are to be built and maintained so that water cannot enter in large quantities, thus causing ground instability or caving.

22.15.3 – All mine drives or tunnels should be designed and built making them safe for the machinery and equipment operators using them, ensuring a comfortable position and avoiding the accidental contact with roof or walls.

22.15.4 – In mining stopes, no development of other work must take place, which might lead to instability or lack of safety.

22.15.5 – Openings must be protected and marked should there be a risk to personnel and materials.

22.15.6 – Underground openings and stopes should be occasionally inspected for the identification of unstable blocks. – Inspections should be undertaken with special care, when restarting work in the stopes after blasting.

22.15.7 – When unstable blocks are found, the area should be isolated until their removal. – When loose rock is found, it immediately should be removed. – The removal of loose rock or unstable blocks should be undertaken by using the adequate tools, which must be available in all mine stopes. A qualified workman following mining company or hand mining permit holder procedures should do this job.

22.15.8 – When driving tunnels, main levels, or clearing mined out sectors, weathered zones or in areas where geological disturbances have taken place, adequate safety procedures must be followed.

22.15.9 – The shaft bottom should be lowered beyond the last level, adequately sized and fitted with a drainage system. It should be cleaned out periodically for safety purposes.

22.15.10 – The dismantled materials store close to the shaft and incline access, should be adequately protected against landslides or placed at a distance of more than 10m from the opening.

22.15.11 – Access routes, passageways and other openings having an inclination of more than 35º, must be protected to avoid landslides and the consequent risk to people and supplies.

22.16 – Handling and Lining of Underground Openings
22.16.1 – All underground openings should be evaluated and receive attention according to their hydro-geo-mechanical features and the purpose for which they are used.

22.16.2 – The evaluation undertaken and the method of attention received should be contained in the mining plan. – In all mines needing attention, the updated plans must be available with the types of attention required. – The plan of attention should include:

a) technical support for the type of action adopted;
b) graphic representation;
c) precise instructions in accessible language, for the erection methods and the local conditions requiring attention;

22.16.3 – Supervisory personnel should systematically and periodically inspect the mine for corrective measures required.

22.16.4 – Should the corrective measures be inadequate, additional action must be taken, to prevent rock massif collapse and destructuring.

22.16.5 – The engineer responsible for the mine will define the areas in which the shoring will be renovated or replaced, duly approve the methods used, and the dismantling sequence and the equipment to be used for the work of renovation or replacement. – The work of renovation is to be undertaken only by qualified workmen.

22.16.6 – All shoring material must be protected for dampness, decomposition, corrosion, apart from other types of deterioration, due to its scheduled useful life.

22.16.7 – The use of hydraulic jacks for mine support purposes must be associated with instruments that detect eventual movement of the rock.

22.17 – Dust Suppression and Control
22.17.1 – At surface or underground where dust is generated, the mining company or hand mining permit holder must undertake periodical monitoring of the workers’ exposure, through evaluating similar exposure groups and the control methods used, recording the data observed as by Table I at least. – A Similar Exposure Group can be described as a group of workmen that experience similar dust exposure, so that the result supplied by the evaluation of any single workman in the group, is also representative of the exposure of the remaining workmen in the same group.

22.17.2 – When the limit of exposure to mineral dust has been exceeded, technical and administrative measures should be taken to reduce, eliminate or neutralize its effects on the workmen’s health and the use of the Action Levels established in this standard should be considered.

22.17.3 – Water should be available in all the mine to be used in suppressing the dust generated in the headings, where rock or ore is being drilled, cut loose, detonated, unloaded or hauled. – Wet drilling and cutting should be used to avoid the dust caused by mining operations. – Should the use of water be unwise due to rock qualities, technical difficulties or when the water could cause additional risks, other means should be used for dust control.

22.17.4 – Dust generating equipment should be fitted with devices that eliminate or reduce the dust count, and must be kept in good operating condition.

22.17.5 – Machine surfaces, installations and the ground used for personnel transit and equipment traffic, must be watered occasionally and cleaned down to avoid dust dispersion on working levels of the mine.

22.17.6 – Enclosed or isolated work stations must be fitted with suitable cooling systems able to offer comfortable working conditions as determined in NR17, and especially sub-item 17.5.2, thus allowing work to be undertaken in sealed airtight conditions.

22.18 – Communication Systems
22.18.1 – All underground mines must have a standardized system to communicate with the haulage facility in shafts and inclines.

22.18.2 – The hoist operator must be informed through the system of communication when personnel are to be conveyed in shafts and inclines. – Should the mine not have a standard code system for communications, the basic signalling code, both by sound and light signals, must follow the table below:

Number of calls Type of call Action required
1 long Stop
1 short Up
2 short Down
3 short Personnel entering/leaving
3+3+1 short Up slowly
3+3+2 short Down slowly
4 short Personnel haulage begins
4+4 short Personnel haulage ends
5 short Signalman entering cage
1 continuous Emergency – The code communication system must be placed in a visible position at all hoist stops and in the hoist room.

22.18.3 – When a fault in the communication system is detected, that could compromise safety, all mine transport must cease, the supervisors should be informed and the necessary repairs made at once.

22.18.4 – Every communication system must have a return signal device that proves to the sender that the receiving party got the message correctly.

22.18.5 – The following mine sectors should be inter-connected through telephone service or other means of communication:

a) mine supervision;
b) close to the working stopes;
c) safety and occupational health sector;
d) maintenance sector;
e) main ventilation plant;
f) main substation;
g) at every shaft level access and access to mine inclines;
h) explosives magazine watchman’s position;
i) on duty fire-fighting and fire prevention team;
j) transport expediter;
k) rooms for ore treatment control;
l) emergency refuge shelter. – The telephone lines should be independent and duly protected to avoid contact with power lines.

22.18.6 – In mines containing firedamp the system of communication should be explosion-proof.

22.19 – Sign-posting Work Sites and Traffic Corridors
22.19.1 – Circulation routes and mine accesses should be adequately sign-posted to ensure miners’ safety.

22.19.2 – Sectors in which inflammable materials are used, and those subject to explosions or fires must be sign-posted, indicating that the area is dangerous and that smoking and the use of matches is not allowed. – Work in the areas mentioned in this item, producing heat, sparks or flames, can only be undertaken when using special procedures or after written authority of responsible engineer in compliance with the provisions of sub-item 22.3.3. (Amended by Ordinance SIT No.27, October 1, 2002)

22.19.3 – Tanks and storage space for toxic substances, inflammable fuels, explosives and materials generating explosive gases, must have signs warning of the danger and the prohibition of using open flames close to or within the access route used by authorized workmen.

22.19.4 – The toxic substance stores, the explosives magazines and the tanks housing inflammable fuels, must have a notice in a visible position showing the type of product housed and the maximum store keeping capacity.

22.19.5 – All signalling apparatus must be kept in perfect operating condition.

22.19.6 – All principal mining horizons must be identified and sign-posted in a visible manner. – At all crossings and main ramifications, directions should be given showing mine exits including emergency exit routes.

22.19.7 – All treatment plants must have their roadways and exits duly identified and sign-posted in a visible manner.

22.19.8 – Depleted or now unmined sectors underground must continue to be sign-posted and interdicted, with access allowed only to authorized personnel.

22.19.9 – Surface areas being mined or that have now been abandoned and are dangerous due to their condition or depth, should be fenced-off and sign-posted or guarded to avoid inadvertent access.

22.19.10 – All piping should be identified as provided in the Brazilian technical standard NBR 6493 – Use of Colors for Identification of Pipes or, alternatively, identified at every 100m, stating the nature of their contents, flow direction and the working pressure under which they operate. (Amended by Ordinance SIT No.27, October 1, 2002)

22.19.11 – Containers with toxic, hazardous or inflammable products, shall be suitably labeled according to existing regulations, indicating at least the composition of the material used. (Amended by Ordinance SIT No.27, October 1, 2002) – At storage sites, where toxic, dangerous or inflammable products are handled and used, emergency cards must be available showing clear and accessible information regarding health risks and the measures to be taken in case of spilling or accidental contact.

22.19.12 – Areas in which tip-trucks operate should be well sign-posted, duly limited and protected against accidental falls of personnel and equipment.

22.19.13 – Access to the mine benches must be duly sign-posted and identified.

22.20 – Electrical Installations
22.20.1 – When work is in progress on electrical installations, the responsible mine engineer must ensure that at least one electrician is present.

22.20.2 – Electrical installations and services must be designed, installed, operated, maintained, renovated and expanded, so as to ensure that power distribution and insulation, current leaks, short-circuits, electrical shocks and other risks, afforded by the use of electric power, cannot be passed on to the consumer.

22.20.3 – Wires and cables used for electric power distribution must be certified by an entity which has been duly accredited by the National Institute of Metrology, Standardization and Industrial Quality-INMETRO.

22.20.4 – When installing transformers and capacitors, their panels and respective operating devices, the following requisites must be considered for the site of installation:

a) it must be well-ventilated and well-lit, or designed and built with the technology required for operating in confined environments;
b) it must be built and anchored in a safe manner;
c) it should be duly protected and marked, indicating a danger zone and warning that access is prohibited to non-authorized personnel;
d) it cannot be used for purposes other than those defined in the electrical project;
e) it must be fitted with portable fire extinguishers covering the existing class of risk, and should be located at the mine adit or in its proximity. When installed underground it should be placed upstream from the ventilation flow.

22.20.5 – All cables, installations and equipment must be protected against impacts, water action and the influence of chemical agents, considering their application according to technical specifications.

22.20.6 – Maintenance services or repairs to electrical systems must only be done when the systems are disconnected, duly marked and earthed, except in the following cases:

a) where special techniques are used for live circuits;
b) when special tools and equipment are used for the voltages in question;
c) when special care is taken for workmen’s safety. – During maintenance and repairs to electrical installations, all equipment must be duly padlocked and marked visibly, containing at least the following indications:

a) hour and date when blocked;
b) reason for maintenance operation;
c) name of whom responsible.

22.20.7 – Emergency machinery and equipment, designed to maintain the continuity of power supply and safety conditions at work, must always be kept in good operating condition.

22.20.8 – Power reticulation, transformers, electric motors, machinery and electrical circuits, must be equipped with automatic protection devices, in the case of short-circuits, overloads, phase drop and current leakages.

22.20.9 – Power lines installed in the roof of tunnels or drives for supplying electrical equipment, must be placed at a height at which there will be no risk to the safe transit of personnel and equipment. These lines must also suitably be protected for accidental contact.

22.20.10 – Automatic reeling systems for cables and wires supplying power to mobile electrical equipment, must be duly earthed to the main equipment frame.

22.20.11 – All mobile electrical equipment should be adequately earthed.

22.20.12 – In places where inflammable and explosive gases occur, electrical maintenance work must be undertaken under the control of a supervisor, with the system disconnected and the switchgear padlocked. Gas monitoring should also take place.

22.20.13 – The energized terminals on transformers must be insulated by the use of barriers or other physical means, in order to avoid accidental contact.

22.20.14 – All installations, frames, casings, shieldings or conductors, which are not part of the electrical circuits but through which current might flow, should be earthed if in a position affording possible accidental contact.

22.20.15 – All installations which are not part of the power conducting system, but which might store static electricity and, therefore, generate sparks, should be fitted with an earthing wire.

22.20.16 – The power reticulation system, the earthing points and the lightning arrestors must be revised periodically and the results duly recorded.

22.20.17 – The implementation, operation and maintenance of electrical installations should only be done by a qualified person who must receive continuous training in the handling and operation of fire-fighting equipment and also first-aid training.

22.20.18 – In the case of very risky work, two qualified electricians must undertake it, unless the engineer responsible determines otherwise.

22.20.19 – During maintenance of machinery or electrical installations, adjustments to safety devices and their technical features must not be altered in any way which might cause a drop in efficiency.

22.20.20 – Should machinery or electrical installations prove defective, this should be communicated to the supervisor for immediate corrective action.

22.20.21 – When working on power lines at two or more different points, out of sight of each other, the electricians must use two-way radios or other forms of communication which do cannot cause accidental energizing.

22.20.22 – When using the rails for the electric current return on mine locomotives, electrical connections should be made between the rails.

22.20.23 – Electrical installations which may come into contact with water, must be designed, built and maintained with special care regarding shielding, watertightness, insulation, earthing and protection against electrical faults.

22.20.24 – All power distribution substations must have available, electrical diagrams illustrating the local power network details.

22.20.25 – Electric cables and wires, especially underground, must be installed in such a way that they cannot be damaged in transport, by falling rock or by their own weight.

22.20.26 – Unused parts of the power reticulation system and out of use power inlets, should be disconnected, marked and insulated or removed, when no longer in use.

22.20.27 – Fixed supports must be used in mine inclines, drives and shafts, when installing electric wires and cables.

22.20.28 – Switch-panels must be duly fixed and earthed and their place of installation must be properly ventilated, marked and protected for accidental contact.

22.20.29 – Traction battery charging stations underground must observe the following conditions:

a) to be suitably identified and marked;
b) to be subject to ventilation by mine fresh air, noting that the airflow must first pass over the transformers and then the battery chargers, after which it will enter the return ventilation stale air route;
c) to be separated from other electrical installations and from the equipment maintenance workshop;
d) access allowed only for authorized personnel carrying explosion-proof lamps.

22.20.30 – Drawings and blueprints should be kept in the mine showing the electrical installations and the respective program and records of maintenance procedures.

22.20.31 – In places where explosive and inflammable gases emanate, the electrical installations must be explosion-proof.

22.20.32 – Installations and buildings at surface must have an adequately designed lightning protection system, and occasional inspections to the earthing system must take place.

22.21 – Use of Explosives and Accessories
22.21.1 – All operations involving the use of explosives and accessories, must follow the manufacturers’ safety recommendations, together with those instructions contained in this Standard.

22.21.2 – The handling and use of explosives must be undertaken by duly trained personnel, following the rules and regulations of the Inspection and Control Department of the Army Ministry.

22.21.3 – In each mine where the use of explosives is necessary for breaking ore, the blasting plan must be available for inspection, showing the following:

a) arrangement and depth of holes;
b) quantity of explosives used;
c) type of explosives and accessories used;
d) blasting sequence;
e) loading ratio;
f) resulting volume of broken ore;
g) minimum time required before returning after blasting. – The mine blasting plan shall be prepared by legally qualified professional. (Amended by Ordinance SIT No.27, October 1, 2002)

22.21.4 – When developing the blasting plan, blasting operations and correlated work, this should be supervised by a qualified Blaster, according to existing rules. – The Blaster is responsible for:

a) ordering and requisitioning the withdrawal from the magazines, the transport and the unloading of the explosives and accessories, in the quantities required by the mine stope at which they will be used;
b) direct and supervise the loading of the holes, checking on the quantities loaded and the blasting sequence;
c) before and during the hole loading operation, in the case of mines or stopes subject to gas emanations, request the gas concentration readings, observing the limits determined by sub-item;
d) direct the connection of the loaded holes with the starting fuse;
e) verify that there is nobody else in the stope before lighting the fuse and leaving the site;
f) in development headings, check the adequate operation of the auxiliary fans and the water sprinkler system;
g) check that there are no misfires, but should there be any, adopt the measures suggested in sub-item 22.21.37;
h) inform the stope foreman or shift boss that the blasting operations have ended.

22.21.5 – The location, construction, storage and maintenance of the main and auxiliary magazines housing explosives and accessories, must follow the rules and regulations determined by the Army Ministry.

22.21.6 – Depots for explosives and accessories underground cannot be located close to personnel access routes or mine main ventilation pathways.

22.21.7 – In accesses to explosives and accessories magazines, fire-fighting equipment must be available.

22.21.8 – Only fully qualified, trained and authorized personnel belonging to the mining company staff or the staff of the hand mining permit holder, or accompanied by someone suitably qualified as above, are allowed access to magazines for explosives and accessories.

22.21.9 – Underground magazines for explosives / accessories should:

a) contain at most the quantity used for a period of five working days;
b) be protected from accidental impacts;
c) be locked and under the responsibility of a legally qualified technician;
d) be independent of each other, separate and duly marked and sign-posted;
e) appear on the plan of the mine with its storage capacity shown;
f) be free of excessive humidity and where ventilation makes this possible, maintain the temperature at adequate levels and minimize the flow of gases to the stopes in case of accidents.

22.21.10 – The use of explosives must be controlled by submitting the reports required by the existing Army Ministry regulations. – In all explosives and accessories depots, weekly stocks must be recorded and the records examined and checked periodically by the Blaster and by the Mine Captain.

22.21.11 – Explosives and accessories cannot be stored in other than the appropriate places. – Unused explosives and accessories must immediately be returned to their respective magazines.

22.21.12 – Only miners working in the vicinity of an explosives and accessories magazine on maintenance or within the depot itself, are authorized to approach by a distance of less than 20m.

22.21.13 – Within explosives depots underground and at less than 25m from them, the barrier system must be made up preferably of incombustible material, whilst no other substance may be disposed of there.

22.21.14 – Explosives and accessories are to be stored in their original packing or in appropriate vessels placed on non-metallic surfaces, which should be suitably resistant and free of dampness. – Explosives and accessories shall not come into contact with any material, which may cause sparks or flashes.

22.21.15 – Magazines storing explosives and accessories must bear warning signs containing the word “EXPLOSIVES”, placed in a visible position nearby and on the doors of the depot.

22.21.16 – The transport of explosives and accessories must be undertaken in a specially prepared vehicle in which metal parts do not come into contact with the load, and meet the Army Ministry requirements and the manufacturer’s recommendations. – Loading and unloading must be done with the engine off and the vehicle brakes on.

22.21.17 – Workmen involved with the transport of explosives and accessories should receive specific training for this purpose.

22.21.18 – The transport of explosives and detonating cord simultaneously with accessories and other supplies and people who are strange to the work, is strictly forbidden.

22.21.19 – Hand carrying explosives and accessories must be done in appropriate containers.

22.21.20 – The hoist operator must know in advance that explosives / accessories are to be transported within the mine in shafts and inclines.

22.21.21 – Explosives whose quality has been compromised or has deteriorated, including the product collected from misfires, must be destroyed in accordance with Army Ministry regulations and the manufacturer’s instructions.

22.21.22 – Before drill-hole loading underground, those responsible must verify the following:

a) according to the mining plan, barriers should be in place:
b) that the drill-holes are cleaned out;
c) that ventilation is available and duly shielded;
d) if everyone involved in the process has left the blasting site;
e) that water sprinklers are available and operating at development headings, for cleaning the gases and the dust during and after the blasting operation.

22.21.23 – The use of explosives must obey the following conditions:

a) blasting should be preceded by a siren warning in the case of an open-cast mine;
b) the risk area must be evacuated and duly watched over;
c) blasting times must be previously determined and annotated on visible notice boards at the mine portal and other points of access;
d) refuge shelters should be available for those responsible for the blasting operation;
e) existing technical standards and the manufacturer’s instructions are to be strictly obeyed.

22.21.24 – When blasting to join up two headings, the following criteria must be followed:

a) full withdrawal of all personnel from both headings, when blasting at each heading;
b) blasting should not be simultaneous at both headings;
c) the minimum safe distance must be determined for stopping work in one of the headings.

22.21.25 – When opening dynamite cases or making holes in cartridges, the tools used must not offer the risk of setting off sparks or flames.

22.21.26 – When loading drill-holes only wood, plastic or copper tamping tools are allowed.

22.21.27 – Instruments and devices used for electric detonation and resistance measuring, must be inspected and calibrated periodically, with a record kept of the last inspection.

22.21.28 – In mines with proven emanations of inflammable or explosive gases, only explosives adequate for these conditions will be allowed.

22.21.29 – Explosives may not be primed beyond the area of the working stope.

22.21.30 – The fixing of the blasting cap to the fuse must be done with a special crimping tool.

22.21.31 – The use of matches, lighters, exposed flames or any other item generating sparks or flames during the handling and transport of explosives and their accessories, is strictly forbidden.

22.21.32 – Electric detonating cord must have the following features:

a) the wire must be copper or galvanized iron;
b) the wire must be insulated;
c) the electric resistance of the wire must be less than the circuit resistance;
d) no joints or repairs must exist;
e) the cord must be kept in short circuit until connected up to the detonators;
f) the cord will be connected up to the detonators by the Blaster, after everyone has left the blasting area;
g) the cord must be of adequate length to allow the Blaster the safe distance he requires.

22.21.33 – In mines having low air humidity, subject to the accumulation of static electricity, the Blaster should use an earthing ring or other such similar device, during assembly of the electric detonating circuit.

22.21.34 – Blasting is forbidden in open cast mines with little lighting or when a lightning storm is in progress. – Should the stope or heading be partly or fully charged, the area must be evacuated immediately.

22.21.35 – When sinking shafts or inclines, the following additional requisites are necessary:

a) the transport of explosives and accessories to the place of use can only be done separately and after all unauthorized personnel have left the site;
b) before connecting up the electric blasting caps to the detonating cord, all electrical installations in the shaft or incline must be disconnected;
c) detonation can only take place from surface or from intermediate levels;
d) shaft and incline operators must be duly informed of the start of charging operations.

22.21.36 – The return to the stope after blasting is only allowed after authority by the area foreman is received and after the following conditions have been checked:

a) all gases and dust have dissipated, as determined by the ventilation project and the blasting plan;
b) after rock stability in the area has been confirmed;
c) misfired holes have been marked and eliminated;

22.21.37 – When misfiring is found or suspected, after the return to the stope or heading, the following action must be taken:

a) all work must cease immediately;
b) the site must be evacuated;
c) the Blaster must be informed, so that proper action is taken. – The removal of misfired charges can only be done by the Blaster or under his personal direction by qualified and trained personnel.

22.21.38 – The removal of misfired charges can only be done by using tools or devices which are free of sparking.

22.21.39 – Explosives and accessories left over after charging or those that may have misfired, should be collected up and taken to their respective depots, after primers have been removed using separate containers.

22.21.40 – The reuse of misfired material is strictly forbidden.

22.22 – Floating Dredge Operations
22.22.1 – Floating dredges which operate in the mineral sector, apart from the regulations governing Marine Work to which they are subject, must also meet the following minimum requisites:

a) the dredge platform must be fitted with hand-railings;
b) all equipment must be securely fastened to avoid displacement;
c) a warning alarm must be available for emergencies;
d) life-belts for all workmen must be available;
e) the maximum load capacity must be indicated on a board in a visible position.

22.23 – Hydraulic Mining
22.23.1 – The workmen and equipment used in hydraulic mining, must keep an adequate distance so as to be protected from possible cave-ins or landslides.

22.23.2 – Unauthorized personnel are not allowed on the pit or bench slope where hydraulic mining takes place.

22.23.3 – Hydraulic mining personnel must wear protective clothing suitable for work in very wet conditions.

22.23.4 – In hydraulic mining installations operating with water pressures of over 3 kg/cm2, the following additional requisites should be observed: (Amended by Ordinance SIT No.27, October 1, 2002)

a) the pipes, pipe fittings and high pressure pipe supports should be suitable for this purpose and provided with devices that avoid the whipping action of the hose in case of accidental detachment; (Amended by Ordinance SIT No.27, October 1, 2002)
b) a support should be available for the hosing equipment;
c) the installation must be fitted with a mechanism which disconnects the pressure pump in case of emergency.

22.24 – Underground Ventilation
22.24.1 – Work underground must be supported by a mechanical ventilating system meeting the following requisites:

a) ensure an adequate supply of oxygen;
b) ensure continuous air renovation;
c) must be capable of the efficient dilution of inflammable gases and dust in the work place;
d) ensures adequate temperature and humidity for human labour;
e) will be maintained and operated in a regular and continuous manner. – The action levels required for implementation of preventive measures, should be as set out in this standard.

22.24.2 – A ventilation project must be prepared and implemented for each mine, with a flow diagram which should be periodically updated, containing at least the following data:

a) location, flow rate and working pressure of the main fans;
b) direction of air flow;
c) location and purpose of all doors, barricades, curtains, dykes, screens and other systems and devices used in controlling the flow of ventilating air. – The ventilation flow diagram must be available to the workmen or their representatives and government authorities. – A schematic ventilation flow diagram for each level of the mine, must be placed on a notice board at each respective level.

22.24.3 – All work areas in development and mining must be ventilated with fresh air so as to prevent workers from being exposed to contaminants above the legal tolerance limits. (Amended by Ordinance MTE No.732, May 22, 2014)

22.24.4 – The same shaft or incline cannot be used for leading the air in and out of the mine, except during development, by using inlet and exhaust ventubing or through a system ensuring that the fresh and stale air do not mix.

22.24.5 – In mines having emanations of firedamp, the stale air current must be directed upwards. – The stale air stream may only be directed downwards for a well-justified technical reason.

22.24.6 – In places with personnel at work or in transit, the oxygen concentration in the air must not be less than 19% in volume.

22.24.7 – The air flow required in coal mines at each working stope, must be at least 6m3/minute per person. – The fresh air flow in coal mine drives or tunnels formed by the last holed through cross-cut, should be at least 250m3 / minute. – In other mines, the amount of fresh air at the stopes should be at least 2m3/minute per person. – When using diesel driven vehicles or equipments operating on diesel with a maximum sulfur content of 50 ppm and engines compatible with PROCONVE – Air Pollution Control Program for Motor Vehicles – P7 emission standard, the flow of fresh air at the working headings should be increased by 2.65m3 /minute for every hp installed. (Amended by Ordinance MTE No.732, May 22, 2014) – When using diesel driven vehicles or equipments operating on diesel with a sulfur content above 50 ppm and engines not compatible with PROCONVE – Air Pollution Control Program for Motor Vehicles – P7 emission standard, the flow of fresh air at the working headings should be increased by 3.5m3 /minute for every hp installed. (Amended by Ordinance MTE No.732, May 22, 2014) – When using diesel driven vehicles or equipments operating on diesel with a maximum sulfur content of 50 ppm and engines compatible with PROCONVE P7 emission standard, in the development headings, the following formula for calculating the fresh air flow at the stopes, should be used: (Amended by Ordinance MTE No.732, May 22, 2014)

QT = 2.65 (P1 + 0.75 x P2 + 0.5 x Pn) [m3 /min]


QT = total fresh air flow in cubic meters per minute
P1 = HP of the largest equipment in operation
P2 = HP of the second largest equipment in operation
Pn = Sum of the HP of the remaining equipment in operation – When using diesel driven vehicles or equipments operating on diesel with a sulfur content above 50 ppm and engines not compatible with PROCONVE – Air Pollution Control Program for Motor Vehicles – P7 emission standard, the following formula for calculating the fresh air flow at the stopes, should be used: (Amended by Ordinance MTE No.732, May 22, 2014)

QT = 3.50 (P1 + 0.75 x P2 + 0.5 x Pn) [m3 /min]


QT = total fresh air flow in cubic meters per minute
P1 = HP of the largest equipment in operation
P2 = HP of the second largest equipment in operation
Pn = Sum of the HP of the remaining equipment in operation – In the case of development without the use of diesel driven vehicles or mining equipment, the fresh air flow can be determined by using 15m3/minute, per square meter of the area of the heading under development. (Renumbered by Ordinance MTE No.732, May 22, 2014)

22.24.8 – In other mines and other underground mining activities, the fresh air flow at the stopes will be calculated as shown in Table II, the highest air flow figure prevailing.

22.24.9 – The total fresh air flow in the mine, should be at least, the sum of the flow in the development areas and the flow of the remaining mine sectors, calculated as determined in this Standard.

22.24.10 – Air velocity underground should not be less than 0.2 m/s and not more than an average of 8 m/s where there is circulation of personnel. – In special cases, the National Department of Mineral Production-DNPM, may approve an increase to the upper limit from 8 m/s to 10 m/s, after hearing the Ministry of Labour and Employment – MTE. – In shafts, drill holes, chimneys or drives, used exclusively for ventilation purposes, the air velocity may be higher than 10 m/s.

22.24.11 – When passing through ventilation doors causes pressure differences, two doors in series should be installed, allowing one of the doors to remain closed whilst the other is open, during the transit of personnel or equipment. – Ventilation doors can only be put in place or taken down with authority from the Mine Captain.

22.24.12 – In the main air stream, the screens used to separate the fresh air from the stale air in cross-cuts, should be built with bricks or material that is fire-proof or lined with a fire-proof product. – The ventilation screens should be kept in good condition to ensure that an adequate supply of air reaches the working stopes.

22.24.13 – The installation and operation of the main fans and the emergency standby units, should appear on the mining plan ventilation project.

22.24.14 – The ventilation system must at least cover the following requisites:

a) an emergency fan with sufficient capacity to maintain the direction of the air flow, must be available for work in situations such as these, and should be duly foreseen in the ventilation project;
b) fan air inlets must be protected;
c) the main fan and the emergency fan should be installed so as to allow air recycling;
d) an alternative independent power source must be available to operate the emergency system in the following situations:
I – in mines in which explosive and toxic gases tend to accumulate;
II – in mines in which the lack of proper ventilation places the workmen at risk during their withdrawal. – Should an independent power source be unavailable, the Mine Captain immediately must order the evacuation of the mine.

22.24.15 – The ventilation plant housing the main and emergency units should be equipped with air pressure measuring instruments.

22.24.16 – The main fan should be fitted with an alarm to indicate a shutdown.

22.24.17 – Fans to be installed in the stopes should have explosion-proof motors.

22.24.18 – All development headings after advancing 10m, and underground work with no communication or situated in a cul-de-sac, should be ventilated by an auxiliary ventilating system with the fan installed in a position that avoids having the air re-circulate. – The fan starter should be placed in the fresh air stream.

22.24.19 – Whenever an auxiliary fan is installed or removed, a diagram must be made to be approved by the mine ventilation engineer.

22.24.20 – Auxiliary fans should not be turned off whilst miners are in the stopes, unless the fan system itself is under maintenance and after all personnel have left, only the maintenance team remaining and following the procedures drawn up for situations such as these.

22.24.21 – The use of compressed air for ventilating purposes is forbidden, except for emergency situations or when compressed air is used for removing impurities. – The exhaust from pneumatic rock drills cannot be considered ventilating air.

22.24.22 – Personnel involved in ventilation and all mine supervisory level personnel working underground, should receive training in the basics of mine ventilation.

22.24.23 – Monthly readings should be taken of the air velocity, airflow and dry and wet bulb temperatures, with the following locations to be considered:

a) downcast ventilation routes;
b) production and development stopes;
c) main fan. – The results of these readings must be duly recorded in appropriate log books.

22.24.24 – In mines with firedamp occurrences, or toxic gas, explosives or inflammables, their concentration control must be made in each shift, at the stopes and headings and at important ventilation points.

22.25 – Ore Dressing and Treatment
22.25.1 – Ore treatment equipment and facilities must be installed at a suitable distance from each other, allowing:

a) the transit of personnel in safety;
b) the undertaking of maintenance;
c) space for product by-pass in case of equipment breakdown;
d) the putting in place of other equipment required for repairs and maintenance.

22.25.2 – Special safety measures are required when working on the following equipment:

a) feeders;
b) ball mills;
c) skimmers;
d) anchorages;
e) continuous conveyors;
f) thickeners;
g) storage and transfer bins;
h) other items used in operations involving slicing, stirring, milling, mixing, storage and pulp conveying. – The special safety measures mentioned must include at least the following:

a) use of a safety belt attached to lifesaver cable;
b) supervision of all work;
c) all equipment must be disconnected, de-energised, with controls duly locked, braked and labeled;
d) equipment to be previously unloaded and ventilated;
e) prior monitoring when applicable for:

I – air quality;
II – explosion risk;
III – ionizing radiation when using radioactive meters. – Only the employee responsible for locking equipment starting controls, may unlock them, following duly recorded procedures.

22.25.3 – In cases where manual labour assists the gravity feed of crushers, other equipment or in places where there is the risk of falling, the compulsory use of a firmly attached safety belt is required.

22.25.4 – Where sample collecting is required, this must be done following written procedures, whilst the equipment must be placed in a safe place for this purpose.

22.25.5 – Where there is a risk of material or people falling or coming into contact with moving parts, circulation areas should be adequately sign-posted and protected.

22.25.6 – The operation of any item of equipment can only be done by authorized personnel, through the use of a system or starting procedure which avoids accidental starting. – All workmen involved or affected by the operation must receive an audible alarm warning at least 20 seconds before equipment offering significant operating risks is started.

22.25.7 – The site on which heap leaching operations are to be implemented, must be fenced off with notices placed in warning that access is forbidden to unauthorized personnel.

22.25.8 – Heap leaching must be done by trained operators and supervised by legally qualified technicians.

22.26 – Waste, Tailings and Product Disposal
22.26.1 – Waste piles, tailings dumps, product heaps, the dams and storage areas, as well as settling ponds, shall be constructed in compliance with hydro-geological studies and also must comply with the environmental standards, mining regulatory standards and the specifications of the applicable ABNT technical standards, especially NBR 11682 and its amendments. (Amended by Ordinance MTE No.732, May 22, 2014)

22.26.2 – Waste piles, tailings dumps or product heaps and the dams, must be supervised by qualified professional technicians with monitoring of water percolation, ground movement and stability and the possible compromising of the water table. – In serious and imminent risk situations where the dam and slopes might burst, the risk areas should be evacuated and isolated, with monitoring of the process and information given to all personnel who are potentially affected by the situation. – Access to the product heaps, waste piles and tailings dumps, is restricted to personnel employed there.

22.26.3 – Permanent or temporary storage of toxic or dangerous products should be done with care and according to existing safety regulations.

22.27 – Lighting
22.27.1 – Work sites, pedestrian routes or roadways for personnel transport, must have natural or artificial lighting systems which are adequate for these purposes. – The installation of a stationary lighting system is compulsory underground, with the following minimum lighting levels at the places mentioned below:

a) 50 lux at the bottom of the shaft;
b) 50 lux in the hoist room;
c) 20 lux in the main roadways;
d) 20 lux at the loading stations, unloading stations and over continuous conveying systems;
e) 60 lux at the crushing plant;
f) 270 lux in the office and workshops. – In the ore treatment facilities at surface, on gangways and in open storage spaces, the lighting conditions must be those determined in the Lighting Standards contained in the Brazilian Standards Technical Association-ABNT recommendations.

22.27.2 – Surface facilities that depend on artificial lighting, failure of which may subject company personnel to accident risks, must be provided with emergency lighting systems meeting the following requirements:

a) automatic switch-on in case of main system failure;
b) the emergency system must be independent of the main system;
c) the system must provide enough lighting to allow personnel to abandon the facility;
d) the system must be tested and kept in good operating condition. – Should it not be possible to install an emergency lighting system, cap lamps should be available.

22.27.3 – The following work underground must also use supplementary lighting in addition to cap lamps:

a) when checking the risk of rock falls;
b) when checking faults and geological discontinuity;
c) when removing loose rock and unstable blocks;
d) when undertaking electrical and mechanical maintenance in working headings.

22.27.4 – When an explosives magazine requires lighting, it may only be installed outside the building.

22.27.5 – When working inside an explosives magazine, only the use of a torch is allowed.

22.27.6 – When working in an open cast mine at night or under poor visibility conditions, the unloading operation must have sufficient lighting. – When weather conditions prevent good visibility, even with the use of artificial lighting, work must stop and vehicles and mobile equipment must be halted.

22.27.7 – The use of cap lamps is compulsory under the following conditions:

a) for access to underground mines;
b) when moving around at night in the mining, loading and unloading sectors in open cast mines; – Only safety lamps may be used in mines having explosive gas occurrences. – Stand-by cap lamps in good operating condition, must be available close to work sites.

22.27.8 – When working with highly reflective minerals, special eye-ware protection should be available.

22.28 – Fire-fighting and Explosion Prevention
22.28.1 – In mines and facilities subject to toxic gas, explosives or inflammables, the PGR-Risk Management Program, should include actions designed for fire-fighting and prevention of accidental explosions. – The actions meant for fire-fighting and the prevention of accidental explosions should be implemented by the Mine Captain and should include at least the following:

a) appoint a team leader responsible for these services and equipment;
b) record the results of inspections and always keep them updated and available for examination by mine and other authorities;
c) the frequency of inspections will depend on the type of gas and may be changed as required.

22.28.2 – In underground mines the concentration of methane must not exceed 1% in volume. – Should the concentration of methane exceed this limit, all work must stop and the immediate supervisor informed, whilst work continues to reduce this concentration. – When the methane concentration attains a value equal to or higher than 2% in volume, the danger zone must be evacuated immediately and duly interdicted.

22.28.3 – The methane concentration in the air stream must be controlled regularly, according to a program implemented and approved by the Mine Captain. – Blasting is not allowed when the volume of methane in the air stream is higher than 0.8%.

22.28.4 – In underground mines subject to gas concentrations which may cause explosions and fires, survival kits must be available in sufficient quantity for the personnel working in the sector. – Besides the survival kits, fire-proof refuge shelters must also be available, as required in the PGR-Risk Management Program, having the capacity to shelter the miners in case of emergency for the time required, with the following main features:

a) air sealed doors;
b) telephone communication with the surface;
c) drinking water and compressed air availability;
d) easily accessible and identified.

22.28.5 – All mining companies should have written emergency procedures, trained fire-fighting teams and alarm systems. – The teams are to be trained by qualified professional firemen and regular emergency drills should be organized.

22.28.6 – Fire prevention should be undertaken in all mine facilities and must include the following actions:

a) Any inflammable article which may also produce fire or sparks, cannot be carried or used in the mine, with the exception of those items required for underground mining operations;
b) Litter or scrap which may be inflammable must be adequately disposed of;
c) Inflammable products and explosives may not be stored close to transformers, boilers or other equipment and installations using electricity or heat;
d) Welding, cutting and heating by means of an open flame may only be done after all suitable fire-fighting equipment has been provided;
e) Smoking underground is not allowed.

22.28.7 – Calcium carbide lamps must not be used underground.

22.28.8 – In underground mines using belt conveyor systems, fire-fighting equipment must be available close to the belt drive and rollers.

22.28.9 – In coal mines the conveyor belts must be made of fireproof material. – Special measures should be taken in coal mines to avoid an accumulation of coal dust along the moving parts of the belt conveying system, where heat can occur through friction.

22.28.10 – In fresh air inlets, additional precautions must be taken to avoid fires and their possible propagation.

22.28.11 – An underground mine ventilating system must be ruled and equipped with procedures or devices that:

a) avoid that combustible gas from surface fires could penetrate the mine;
b) not allow combustible gas or other toxic gas generated underground as a result of a fire, to be led to the stopes, but be adequately diluted;

22.28.12 – Combustible products, inflammables or explosives must not be stored close to the mine portal.

22.28.13 – Every inflammable product or explosive must be suitably labeled and stored in a safe place which has been duly identified and built according to existing regulations.

22.28.14 – All underground mines must be fitted with water networks and fire-fighting systems and devices.

22.28.15 – Every mine should have fire extinguishers installed suitable for the class of fire risk and must be inspected regularly by trained personnel.

22.28.16 – Fire-fighting equipment, water outlets and the stock of supplies to be used in the building of emergency dykes at surface and underground, must always be duly identified and installed at appropriate and easily accessible sites. – Fire-fighting equipment must be inspected at regular intervals.

22.28.17 – All workmen must be instructed in fire-fighting and fire prevention using portable extinguishers; they must also be given basic first aid training.

22.28.18 – Should a fire be confirmed, the entire risk area should be placed off bounds and all personnel not involved in fire fighting must be evacuated to other safe areas.

22.28.19 – Carpenters’ shops should be away from other workshops and placed beyond any fire or explosion risk areas.

22.29 – Inflammable Dust Explosion Prevention in Underground Coal Mines
22.29.1 – Underground coal mines must identify the sources of dust generation, taking the proper preventive measures to reduce the risk of coal dust fires and the spreading of flames. – The preventive measures in question are to be implemented in the following places:

a) in working stopes;
b) at ore transfer points;
c) at conveyor belt ore loading stations, and
d) where ignition sources are known. – The preventive measures are to be:

a) wet drilling to avoid dust generation in the working stopes;
b) at the ore transfer points and ore loading stations:
I – watering down;
II – neutralization with inert material;
III – washing down the walls, roof and floor of the mine at regular intervals, to be determined for each site, and
c) where ignition sources are known:
I – isolate the source
II – humidifying, or
III – neutralization with inert material.

22.30 – Flood Prevention
22.30.1 – The mining company or the hand mining permit holder should adopt measures to avoid accidental flooding of their installations using the hydro-geological studies foreseen in the mining regulations. (Amended by Ordinance SIT No.27, October 1, 2002) – The following actions should be taken underground:

a) control the amount of water pumped and its fluctuations over time;
b) adopt a suitable communication system whenever there is imminent risk of flooding mine personnel access or exit routes.

22.31 – Radioactive Equipment
22.31.1 – All mining companies using radioactive sources or radioactive measuring instruments in their production processes, should obey the Basic Directives for Radio-protection issued by the National Nuclear Energy Commission-CNEN, especially with regard to NEs nos. 3.01/83; 6.02/84; 3.02/88; 3.03/88 and later amendments.

22.31.2 – The mining company using radioactive sources or measuring instruments, must place its Radio-protection Plan at the disposal of inspectors, together with the results of workmen’s exposure and the radiometric survey results. The calibration certificates for measuring instruments should also be made available.

22.31.3 – All radioactive sources or sectors in which the workmen may be exposed to higher radioactivity doses than allowed, must be duly identified by notices.

22.31.4 – Workmen subject to ion radiation exposure and those who cross radioactive sectors, must be informed about the equipment in use and the risks they run.

22.31.5 – Work involving ion radiation must be directed by a Radio-protection Supervisor duly qualified by CNEN.

22.31.6 – Supplementary radioactive sources and those now unused, should be stored according to CNEN rules and recommendations.

22.32 – Emergency Operations
22.32 1 – Every mine must itself prepare, implement and keep updated an emergency plan, which should include at least the following requisites:

a) a list of the major risks involved in the mine operation;
b) procedures to be followed in the case of:

I) fires;
II) floods;
III) explosions;
IV) cave-ins;
V) ventilation system power failure;
VI) major accidents;
VII) other emergency situations as determined by the features of the mine, its products and the raw materials used.

c) location of equipment and supplies required for emergencies and first-aid rendering;
d) emergency brigade members and procedures to be followed for situations as described in items I to VII;
e) regular training program for emergency brigades;
f) regular simulation rescue exercises mobilizing the mine contingent directly affected by the event;
g) defining areas and installations duly built and equipped to act as shelter for victims and first-aid personnel;
h) defining communication systems and emergency alarms in both the company and outside environments, and
i) company agreements with civil defense organizations.
j) establishment of a system that allows to know the names of all the people who are underground, as well as their probable location, with precision and at any moment. (Inserted by Ordinance MTPS No.506, April 29, 2016) – Supervisors must be aware of and disclose the emergency procedure plan to all their subordinates.

22.32.2 – The company must offer a six-monthly training program for the emergency brigade, including theory and practical learning.

22.32.3 – Simulation exercises should take place annually in which the full duly affected mine contingent should be included.

22.32.4 – All underground mines should have a refuge area for emergency situations, duly built and equipped for sheltering rescue personnel and offering first-aid facilities.

22.33 – Emergency Exits and Escape Routes
22.33.1 – It is compulsory that all working underground mines should have at least two access routes leading to the surface, one being the main route and the other an alternative or emergency route, both independent of each other but connected up by secondary tunnels, so that should one become obstructed the other may be used instead. – The contents of this item do not refer to a mine in its implementation or shaft sinking stage.

22.33.2 – For an underground mine in normal operation, the main and secondary pathways must allow everyone to reach the surface from their work stations, through either of these two routes, one of which is the emergency route.

22.33.3 – The layout of work stations underground must be such as to allow the workmen safely to evacuate the mine. The number and distribution of personnel throughout the mine must appear on the emergency plan as required in sub-item 22.32.1.

22.33.4 – The escape routes and emergency exits must be aimed as directly as possible to the surface, from concentration points which were previously determined and suitably marked.

22.33.5 – The escape routes and emergency exits as well as the circulation pathways and the doors leading to them should be duly marked and remain unobstructed.

22.33.6 – The inclines and upcast ventilation routes used as emergency exits, must be fitted with ladders to be built and installed as prescribed in item 22.10.

22.34 – Mine Shutdowns and Restarting Operations
22.34.1 – When mining ends either temporarily or permanently, the mining company or the hand mining permit holder, must inform the local Ministry of Labour office and the DNPM, and follow all mining legislation requirements.

22.34.2 – Mines which have been permanently shutdown, must have all their adits or portals duly sealed, as required by existing legislation.

22.34.3 – In order to restart operations once again, the mining company or the hand mining permit holder must provide for the following:

a) re-evaluate the status of mine conservation, its installations, equipment and systems;
b) re-establish mine hygiene and work safety;
c) ventilate all underground mine stopes before re-entering, and monitor air quality;
d) dewater all flooded mine sectors;
e) check on mine structure stability, reinforcing where damaged;
f) undertake studies and additional projects called for by the inspecting authorities, and;
g) have available for the inspecting authorities, the permit issued by DNPM allowing mining to start once again.

22.35 – Information, Qualification and Training
22.35.1 – The mining company or the hand mining license holder must offer their workmen training, qualification, information and the recycling necessary to maintain their safety and occupational health levels, taking into consideration the risk factor involved in the nature of their work. – Training received on admittance by workmen underground or those transferred from the surface to underground employment or vice-versa, should include the following topics:

a) general introductory training gaining knowledge of their work place;
b) specific job training;
c) guidance at work. – General introductory training should take at least six hours daily during five days for underground work, and eight hours daily during three days for work at surface. This training program will be undertaken during working hours and should contain the following minimum curriculum:

a) operational mining cycles;
b) main items of equipment and their purpose;
c) mine infra-structure;
d) power distribution;
e) supply of materials;
f) mine transport;
g) rules observed for personnel and equipment circulation;
h) emergency procedures;
i) first-aid;
j) disclose existing risks at the work place as described in the Risk Management Program, together with accident prevention and occupational diseases;
k) full knowledge of the work place. – Specific on-the-job training will consist of theoretical studies and the practical side of the job in question, the risks involved, their prevention, correct procedures to be followed, and should have a minimum work load of forty hours for surface activities and forty-eight hours for underground work. This training schedule is to be undertaken during working hours and the newly hired worker’s test period, or before job changes. – The mining company or the hand mining permit holder must offer specific training with regular recycling to all workmen whose jobs include:

a) removing loose rock;
b) rock massif handling;
c) handling of explosives and accessories;
d) hand drilling;
e) material loading and transport;
f) scraper winch operations;
g) operating winches and lifting mechanisms;
h) stope inspection;
i) handling and manipulation of toxic or dangerous products;
j) other work and risk operations mentioned in the RMP. – On-the-job training will consist of a period during which the workman will do his job under the direction of an experienced workman or under his direct supervision for at least forty five days. – Regular training and when specific situations arise, will be offered whenever necessary, so that the job can be done as safely as possible.

22.35.2 – When operating machines, equipment or processes to which the operator is unaccustomed, further training must be given to qualify him in their use.

22.35.3 – Directions will be required to be given to workmen who have been away from work for more than thirty consecutive days, on the existing conditions of mine circulation routes and roadways.

22.35.4 – Instructions concerning information, qualification and training passed on to the workmen must be written in comprehensible language, whilst methods, techniques and materials should be adopted that make learning easier and help to preserve their safety and health.

22.35.5 – Considering the features of the mine and its mining and treatment methods, the regional safety and occupational health authorities may require other types of training.

22.36 – Internal Committee for Accident Prevention in Mining-CIPAMIN
22.36.1 – The mining company or the hand mining permit holder, hiring workmen as their employees, must organize and maintain in regular operation as described in this Standard, and for each establishment, an Internal Committee for Accident Prevention in Mining, henceforth known as Mining CIPA or CIPAMIN.

22.36.2 – The aim of CIPAMIN is to observe and report on the risk conditions at the work place, in order to prevent accidents and diseases arising from mining activities, making this work compatible with the safety and occupational health of the workmen.

22.36.3 – The CIPAMIN committee will be formed by members representing the employer and the employees, together with their respective alternates or deputies, according to the ratios appearing on Table III attached. – The CIPAMIN organization must follow certain criteria in which sectors offering the highest risks or that have the largest number of work accidents, are duly represented. – The high risk sectors are determined by CIPAMIN on the basis of data supplied by the RMP in the annual report presented by the PCMSO for work accident statistics prepared by SESMT, and other data and information concerning safety and occupational health, available within the company. – When the establishment does not conform to Table III of this Standard, the mining company or hand mining permit holder shall designate and train in accident prevention, a representative who will fulfill CIPAMIN’s objectives, and ensure that the workmen’s representatives take part in all actions aimed at preventing accidents and professional illnesses.

22.36.4 – The employees’ representatives on the CIPAMIN committee will be elected by the workmen following procedures set out in NR5 – CIPA and according to the criteria mentioned in item 3.1. – In obedience to the criteria given in item 3.1 for the composition of the CIPAMIN committee, this committee itself will be responsible for indicating the sectors to be individually represented by an employee. – According to Table III, which gives the suggested number of committee members on the basis of the number of employees in each size establishment, the CIPAMIN committee will be formed so as to represent all company sectors and may if necessary, group together certain areas or sectors whose work is similar or complementary. – The interested candidates should register their names in order to represent the department or sector in which they work. – Elections will take place by area or sector, and the employees therein will ballot for the registered candidates in their own area or sector. – The candidate with the largest number of votes for his area or sector will become a titular CIPA committee member. – The chosen deputy or alternate, based on Table III, amongst all other candidates, will be the one with the largest number of votes, ignoring the area or working sector. – The term of office for CIPA elected members will be 1 (one) year, and one re-election to office is allowed.

22.36.5 – The CIPAMIN President and the employer’s alternate representative, are to be indicated by the employer.

22.36.6 – The CIPAMIN Vice-President will be chosen from the employees’ titular representatives.

22.36.7 – The CIPAMIN duties are as follows:

(a) prepare the Risk Map as prescribed in NR5 (CIPA), forwarding it to the employer and to SESMT;
(b) recommend the implementation of actions meant to control the identified risks;
(c) analyze and discuss work accidents and professional diseases, proposing and requesting preventive actions to avoid their recurrence and informing the remaining workmen about their prevention.
(d) carry out permanent negotiations within the bounds of their representation, to recommend and request the employer to implement control measures;
(e) follow the implementation of control measures and actions chronogram, established by the RMP and PCMSO;
(f) participate in regular inspections of the work places, as scheduled by the company or SESMT, following the time chart agreed with the employer;
(g) hold regular monthly meetings held in an appropriate place and during working hours, following an annual calendar, and with minutes duly prepared and in accordance with NR5; (Amended by Ordinance SIT No.202, January 26, 2011)
(h) hold extraordinary meetings when fatal accidents occur or accidents take place which cause the loss of a limb or bodily function, or which may cause large losses, within 48 (forty-eight) hours of its occurrence;
(i) request SESMT or the employer to give prior notice of the impact to the workers safety and occupational health, which new projects or significant changes to the environment or plant process may cause, revising the Risk Map accordingly;
(j) requisition the mining company or the hand mining permit holder to supply copies of the Work Accident Reports issued;
(k) present to newly-hired workmen during their training, their aims, duties and responsibilities, as foreseen in item 22.35;
(l) hold annually the Internal Mining Work Accident Prevention Week- SIPATMIN, disclosing the results of the actions taken by CIPAMIN;

22.36.8 – The employer must provide CIPAMIN with the means and conditions necessary to carry out its duties.

22.36.9 – The duties of the President of CIPAMIN are the following:

a) co-ordinate and control CIPAMIN activities;
b) call the members to ordinary monthly meetings and the extraordinary meetings when held;
c) prepare the agenda of the ordinary meetings together with the Vice-President;
d) preside over the meetings;
e) forward the Risk Map to the employer and SESMT;
f) forward to the employer and to SESMT the recommendations and requests made by CIPAMIN;
g) care for the proper functioning and provide the necessary means for CIPAMIN to comply with its duties;
h) maintain and promote the relationship between CIPAMIN and SESMT and with all other company sectors;
i) prepare the quarterly report of activities jointly with the Vice-President, forwarding it to the employer and SESMT.

22.36.10 – The duties of the CIPAMIN Vice-President are the following:

a) replace the President in his absence;
b) co-ordinate the employees’ representatives in the preparation and presentation of the recommendations and other actions taken by CIPAMIN;
c) lead the employer’s representatives in discussions and negotiations of the CIPAMIN meeting agenda items;
d) negotiate with the employer concerning the adoption of measures designed to control and correct the risks and improve working conditions, including the designation of a work group to investigate working accidents and to participate in regular inspections of the work sites;
e) should there be a halt in the progress of negotiations as by line “d” above, request that a Ministry of Labour representative visits the company.

22.36.11 – The company will appoint, in agreement with the members of CIPAMIN, a secretary and his alternate who may be Committee members or not. – The duties of the CIPAMIN Secretary are as follows:

a) attend the Committee meetings, writing up the respective Minutes and submitting them for approval and signature of the members present;
b) prepare all correspondence;
c) undertake other duties conferred by the President or Vice-President of CIPAMIN;
d) record in the Minutes all recommendations and requests made by CIPAMIN.

22.36.12 – All CIPAMIN members, effective or alternate, should receive training in accident prevention and professional diseases during normal company working hours. – The training of CIPAMIN members could be done by SESMT, or employers or workers’ unions, or by professionals who have knowledge of the subjects taught, chosen by agreement between the employer and the members of the Committee. (Amended by Ordinance SIT No.63, December 02, 2003) – Companies with up to fifty employees, including those with only designated employees, can organize or participate in joint trainings that address the topics specified in item (Amended by Ordinance SIT No.63, December 02, 2003) – The course curriculum should include accident risks and professional diseases covered in the Risk Management Program, the measures adopted to eliminate and control these risks, together with the techniques needed to prepare the Risk Maps and the methods used for accident evaluations. – The hourly work load for the course on accident prevention and professional diseases should be 40 (forty) hours per annum, of which 20 (twenty) hours will be given before the CIPAMIN members take office.

22.36.13 – Once the CIPAMIN is duly installed, all documentation related to the electoral process, minutes of election and tenure, and the annual calendar shall comply with the provisions of items 5.14, 5.14.1 and 5.14.2 of NR5. (Amended by Ordinance MTE No. 1894, December 9, 2013)

22.36.14 – Should there be service companies or contractors working at the owner’s establishment, who cannot conform to the requirements of Table III of this Standard, they must appoint at least one representative to sit in on the CIPAMIN meetings.

22.37 – General Matters
22.37.1 – The employer shall provide the underground worker with meals which are suitable for the nature of his work, duly supervised by a nutritionist, as required by existing legislation. (Amended by Ordinance SIT No.27, October 1, 2002 – When joining the Workers’ Food Program, the mining company or the hand mining license holder, must obtain prior approval of the regional labour office responsible for the workers’ safety and well-being. – Should food be supplied underground, the mining company or the hand mining permit holder must have a suitable eating place, which meets the conditions of safety, hygiene and comfort for the workmen.

22.37.2 – The mining company and the hand mining permit holder must make clean and hygienic washrooms available for the workmen underground. – Underground litter or garbage containers must be removed to the surface at the end of every shift, for proper disposal of the contents, with due respect to rules governing health and hygiene as well as existing environmental legislation. – Underground washrooms where the WCs are treated by chemical or biological means, must observe the rules governing health and hygiene and the manufacturer’s operating instructions.

22.37.3 – The comfort and hygiene conditions at workstations are determined by NR24 – Sanitary conditions and comfort at work sites. – The mining company or the hand mining permit holder may replace the miners’ individual lockers for other means of saving clothes and personal belongings, thus ensuring that the change-rooms are kept clean and tidy. – Should change-rooms be installed underground, these must follow the same rules as given in sub-items 22.36.3 and

22.37.4 – Drinking water will be supplied to the miners at all workstations.

22.37.5 – For travel to and from the various mining establishments, whether or not a public bus service is available, transport for the workmen may be offered by the mining company or the hand mining license holder, either directly or through a bus hire service, in suitable vehicles for this purpose. Their use will not be compulsory and does not mean that the workmen should be paid for time in transit.

22.37.6 – An updated record of occupational accident and disease statistics must be held by the company, and made available to CIPAMIN, SESMT. (Amended by Ordinance SIT No.27, October 1, 2002) – Accidents and professional diseases must be analyzed using methods that allow the identification of the main causes that led to their occurrence, indicating the measures in use for prevention of further similar occurrences.

22.37.7 – In the case of a fatal accident, the following actions are compulsory:

(a) immediately report the accident to the police authority and to the DRT; (Amended by Ordinance SIT No.27, October 1, 2002)
(b) isolate the accident site, leaving it untouched until the police examination has taken place;

22.37.8 – The cases, which have been omitted from this Standard, will be clarified by the Department of Health and Safety at Work – DSST / MTE.

22.37.9 – The use of this Standard does not exclude the compliance with other provisions established in relevant legislation. (Amended by Ordinance SIT No.27, October 1, 2002)

TABLE I – Number of workmen to be sampled in relation to the number of workmen in the Homogeneous Exposure Group according to item 22.17.1


N = number of workmen in a Homogeneous Exposure Group
n = number of workmen to be sampled
* if N is less than or equal to 7, n = N

TABLE II – Determining the flow of fresh air according to item 22.24.8

A) Calculating the flow of fresh air as a function of the maximum number of people or machinery items having internal combustion diesel-driven engines:

QT = Q1 x n1 + Q2 x n2


QT = total fresh air flow in m3/min
Q1 = quantity of air per person in m3/min (in coal mines = 6.0 m3/min; in other mines = 2.0 m3/min)
n1 = number of people in a working shift
Q2 = 3.5 m3/min/hp of diesel motors
n2 = total hp of diesel driven motors in operation

B) Calculation of fresh air flow as a function of explosives consumption

QT = (0.5 x A) / t


QT = total fresh air flow in m3/min
A = total quantity in kg of explosives employed in each blasting operation
t = time taken for ventilating (re-entering) the stope in minutes

C) Calculation of fresh air flow as a function of the ore tonnage mined

QT = q x T


QT = total fresh air flow in m3/min
q = air flow in m3/min for 1,000 tons of ore mined per month (minimum of 180 m3/ minute/1,000 tons per month)
T = production in tons mined per month

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