NIOSH
Recommended Exposure Limit

A worker's exposure to sound of each intensity level shown in the table should not equal or exceed the duration shown in the table. Durations are calculated from the formula:

An equation. T equals the fraction 480 over 2 to a power which is a fraction. The numerator is L minus 85 and the denominator is 3.

where T is duration in minutes and L is exposure level in dBA.

Exposure Level
(dBA)
Duration
Hours Minutes Seconds
80 25 24 0
81 20 10 0
82 16 0 0
83 12 42 0
84 10 5 0
85 8 0 0
86 6 21 0
87 5 2 0
88 4 0 0
89 3 10 0
90 2 31 0
91 2 0 0
92 1 35 0
93 1 16 0
94 1 0 0
95 47 37
96 37 48
97 30  0
98 23 49
99 18 59
100 15  0
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
130–140 less than 1

Source: U.S. Dept. of Health and Human Services. Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health.
Criteria for a Recommended Standard. Occupational Noise Exposure. Revised Criteria 1998.
Cincinnati (OH): June 1998.

home | properties index | search |  contact drawing of envelope |  contributors | 
help | privacy | terms of use