NOISE LEVEL dB (A) | MAXIMUM PERMISSIBLE DAILY EXPOSURE |
85 86 87 88 89 90 91 92 93 94 95 96 98 100 102 104 105 106 108 110 112 114 115 |
8 hours 7 hours 6 hours 5 hours 4 hours and 30 minutes 4 hours 3 hours and 30 minutes 3 hours 2 hours and 40 minutes 2 hours and 15 minutes 2 hours 1 hour and 45 minutes 1 hour and 15 minutes 1 hour 45 minutes 35 minutes 30 minutes 25 minutes 20 minutes 15 minutes 10 minutes 8 minutes 7 minutes |
1. For the purposes of application of Tolerance Limits, noise, which is not impact noise, is considered as Continuous or Intermittent Noise.
2. The levels of continuous or intermittent noise shall be measured in decibels (dB) with “A” scale of a sound pressure level meter at slow response (SLOW). The readings shall be made near the ear of the worker.
3. The duration of exposure to noise shall not exceed the tolerance limits set out in the table in this Annex.
4. For the actual values for intermediate noise levels, maximum permissible daily exposure relating to immediately-higher level shall be considered.
5. Exposure to noise levels above 115 dB(A) is not allowed to the individuals who are not adequately protected.
6. When the daily noise exposure is composed of two or more periods of noise exposure of different levels, their combined effect should be considered, so that, if the sum of the following fractions:
C1/T1+ C2/T2+C3/T3+ ————— +Cn/Tn
exceeds unity, then, the exposure is above the tolerance limit.
In the above equation, Cn indicates the total time of exposure at a specified noise level, and Tn indicates the maximum permissible daily exposure at that level, according to the Table in this Annex.
7. The activities and operations that expose workers to noise levels, continuous or intermittent, greater than 115 dB(A), without adequate protection, pose serious and imminent danger.