Annex I of NR9 – Vibration

Summary:
1. Objectives
2. General Provisions
3. Preliminary Exposure Assessment
4. Quantitative Exposure Assessment
5. Preventive and Corrective Measures

1. Objectives

1.1 To set criteria for prevention of diseases and disorders resulting from occupational exposure to the Hand-Arm Vibration (HAV) and Whole-Body Vibration (WBV) within the Environmental Risk Prevention Program.

2. General Provisions

2.1 Employers shall adopt measures to prevent and control exposure to the mechanical vibrations that may affect the safety and health of the workers, eliminating the risk, or where there is no proven technology available, reducing it to the lowest levels possible.

2.1.1 Physical exertions and postural aspects, among other things, shall be considered in the process of eliminating or reducing the risks related to exposure to the mechanical vibrations.

2.2 Employers shall prove the adoption of effective measures to control and reduce the exposure to vibration within the actions of preventive and corrective maintenance of vehicles, machinery, equipments and tools.

2.3 Vibrating hand tools that produce accelerations greater than 2.5m/s2 shall inform with the technical specifications of vibration emitted by those hand tools, indicating the testing standards that were used for the measurement.

3. Preliminary Exposure Assessment

3.1 Preliminary assessment of exposure to the HAV and WBV shall be carried out within the context of risk assessment and recognition, considering the followings:

a) work environments, processes, operations and exposure conditions;
b) characteristics of the machines, vehicles, work equipments or tools;
c) informations provided by the manufacturers on vibration levels generated by tools, vehicles, machinery or equipment;
d) conditions of use and state of conservation of vehicles, machinery, equipment and tools, including isolation and cushioning components or devices that interfere with the exposure of operators or drivers;
e) characteristics of the surface, transported loads and operating speeds, in case of WBV;
f) estimated effective time of daily exposure;
g) specific working conditions that may contribute to the aggravation of the effects of exposure;
h) physical exertions and postural aspects;
i)  data from existing occupational exposure;
j) information or records relating to medical history and complaints of the workers exposed t the vibration.

3.2 The results of preliminary assessment shall subsidize the adoption of preventive and corrective measures, notwithstanding any other measures provided in the remaining NRs.

3.3 If the preliminary assessment is not sufficient to make decisions regarding the need to implement preventive and corrective measures, quantitative assessment shall be carried out.

4. Quantitative Exposure Assessment

4.1 The quantitative assessment shall be representative of the exposure, covering organizational and environmental aspects that involve the workers in the course of their duties.

4.1.1 The procedures of the quantitative evaluation for the HAV and WBV, to be adopted within the scope of this Annex, are those laid down in the Occupational Hygiene Standards published by FUNDACENTRO.

4.2 Quantitative exposure assessment for the HAV

4.2.1 The assessment of occupational exposure to the hand-arm vibration shall be made using measurement systems that allow the determination of acceleration resulting from normalized exposure (aren), parameter representing the daily exposure of the worker.

4.2.2 The action level for assessing the daily occupational exposure to the hand-arm vibration corresponds to a value of acceleration resulting from the normalized exposure of 2,5 m/s2.

4.2.3 The daily exposure limit for hand-arm vibration corresponds to a value of acceleration resulting from the normalized exposure of 5m/s2.

4.2.4 The occupational exposure above the action level, regardless of the personal protective equipment, requires mandatory adoption of preventive measures, notwithstanding the provisions of item 9.3.5.1 of NR9.

4.2.5 The occupational exposure above the occupational exposure limit, regardless of the personal protective equipment, requires mandatory adoption of preventive measures, notwithstanding the provisions of item 9.3.5.1 of NR9.

4.3 Quantitative exposure assessment for the WBV

4.3.1 The assessment of occupational exposure to the whole body vibration shall be made using measurement systems that allow the determination of acceleration resulting from normalized exposure (aren), and of the vibration dose value (VDV), parameter representing the daily exposure of the worker.

4.3.2 The action level for assessing the daily occupational exposure to the whole body vibration corresponds to a value of acceleration resulting from the normalized exposure of 0,5 m/s2, or the vibration dose value (VDV) of 9,1m/s1,75.

4.3.3 The daily exposure limit for whole body vibration corresponds to:

a) value of acceleration resulting from the normalized exposure of 1,1 m/s2; or
b) vibration dose value (VDV) of 21,0 m/s1,75.

4.3.3.1 For the purposes of exposure characterization, the employer shall prove the assessment of two parameters described above.

4.3.4 The occupational exposure above the action level requires mandatory adoption of preventive measures, notwithstanding the provisions of item 9.3.5.1 of NR9.

4.3.5 The occupational exposure above the occupational exposure limit requires mandatory adoption of preventive measures, notwithstanding the provisions of item 9.3.5.1 of NR9.

5. Preventive and Corrective Measures

5.1 The preventive measures shall include:

a) Periodic assessment of exposure;
b) Guidance for the workers about the risks arising from exposure to vibration and appropriate use of work equipments, as well as the right to notify their superiors of abnormal vibration levels observed during their activities;
c) Health surveillance focused on the effects of vibration exposure;
d) Adoption of procedures and alternative methods of work that reduce the exposure to mechanical vibration.

5.1.1 The preventive measures described in this item do not exclude other measures that may be deemed necessary or advisable depending on the particularities of each work condition.

5.2 The corrective measures shall include at least one of the following measures, obeying the hierarchy provided in NR9:

a) In case of exposure to the HAV, modification of process or work operation: replacement of tools and accessories; redesign or reorganization of the workbenches and jobs; changing the routines or work procedures; appropriateness of the type of tool, the accessory used and the operating speeds;
b) In case of exposure to the WBV, modification of process or work operation: redesigning of the work platforms; redesigning, reorganizing or changing the routines or work procedures and organization; appropriateness of the vehicles used, especially by the adoption of anti-vibration seats; the improvement of conditions and the characteristics of the floors and pavements used for movement of machinery and vehicles;
c) Reducing the time and intensity of the daily exposure to vibration;
d) Alternation of activities or operations that generate exposure to higher levels of vibration with others that involve exposure to lower levels of vibration.

5.2.1 The corrective measures mentioned above do not exclude other measures that may be deemed necessary or advisable depending on the particularities of each work condition.