Noise Exposure - Permissible Levels and Duration
Exposure to noise should be controlled so that it is less than a maximum combination of exposure level and duration.
According the National Institute for Occupational Safety - NIOSH - the exposure to noise should be controlled so that the exposure is less than a max combination of exposure level - L - and duration - t.
The maximum time of exposure at a noise level can be calculated as:
t = 480 / 2(L - 85)/3 (1)
where
t = maximum exposure duration (minutes)
L = noise exposure level (dB(A))
3 = exchange rate (dB)
Download and print Noise Level - Maximum Exposure Time Chart
Example - Maximum Exposure Time to Noise
The maximum time a person can be exposed for a noise level 100 dB can be calculated as
t = 480 / 2((100 dB) - 85)/3
= 15 minutes
Maximum Noise Exposure Time Calculator
L - noise exposure level (dB(A))
Combinations of noise exposure levels and maximum duration time:
| Noise Exposure Level (dBA) | Duration Time | ||
|---|---|---|---|
| Hours | Minutes | Seconds | |
| 80 | 25 | 24 | |
| 81 | 20 | 10 | |
| 82 | 16 | ||
| 83 | 12 | 42 | |
| 84 | 10 | 5 | |
| 85 | 8 | ||
| 86 | 6 | 21 | |
| 87 | 5 | 2 | |
| 88 | 4 | ||
| 89 | 3 | 10 | |
| 90 | 2 | 31 | |
| 91 | 2 | ||
| 92 | 1 | 35 | |
| 93 | 1 | 16 | |
| 94 | 1 | ||
| 95 | 47 | 37 | |
| 96 | 37 | 48 | |
| 97 | 30 | ||
| 98 | 23 | 49 | |
| 99 | 18 | 59 | |
| 100 | 15 | ||
| 101 | 11 | 54 | |
| 102 | 9 | 27 | |
| 103 | 7 | 30 | |
| 104 | 5 | 57 | |
| 105 | 4 | 43 | |
| 106 | 3 | 45 | |
| 107 | 2 | 59 | |
| 108 | 2 | 22 | |
| 109 | 1 | 53 | |
| 110 | 1 | 29 | |
| 111 | 1 | 11 | |
| 112 | 56 | ||
| 113 | 45 | ||
| 114 | 35 | ||
| 115 | 28 | ||
| 116 | 22 | ||
| 117 | 18 | ||
| 118 | 14 | ||
| 119 | 11 | ||
| 120 | 9 | ||
| 121 | 7 | ||
| 122 | 6 | ||
| 123 | 4 | ||
| 124 | 3 | ||
| 125 | 3 | ||
| 126 | 2 | ||
| 127 | 1 | ||
| 128 | 1 | ||
| 129 | 1 | ||
| 130 | 1 | ||
| -140 | < 1 | ||
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Daily Noise Dose Level - Daily noise dose when exposed in periods with different noise levels