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1926.52(a)
Protection against the effects of noise exposure shall be
provided when the sound levels exceed those shown in Table D-2 of this
section when measured on the A-scale of a standard sound level meter at
slow response.
1926.52(b)
When employees are subjected to sound levels
exceeding those listed in Table D-2 of this section, feasible
administrative or engineering controls shall be utilized. If such
controls fail to reduce sound levels within the levels of the table,
personal protective equipment as required in Subpart E, shall be
provided and used to reduce sound levels within the levels of the
table.
1926.52(c)
If the variations in noise level involve maxima at
intervals of 1 second or less, it is to be considered continuous.
1926.52(d)
1926.52(d)(1)
In all cases where the sound levels exceed the
values shown herein, a continuing, effective hearing conservation
program shall be administered.
TABLE D-2 - PERMISSIBLE NOISE EXPOSURES
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| Sound level
Duration per day,hours | dBA slow
| response
__________________________________|_____________
|
8..................................| 90
6..................................| 92
4..................................| 95
3..................................| 97
2..................................| 100
1 1/2..............................| 102
1..................................| 105
1/2................................| 110
1/4 or less........................| 115
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..1926.52(d)(2)
1926.52(d)(2)
1926.52(d)(2)(i)
When the daily noise exposure is composed of two
or more periods of noise exposure of different levels, their
combined effect should be considered, rather than the individual
effect of each. Exposure to different levels for various periods of
time shall be computed according to the formula set forth in
paragraph (d)(2)(ii) of this section.
1926.52(d)(2)(ii)
F(e)=(T(1)divided by L(1))+(T(2)divided by L(2))+
... + (T(n) divided by L(n)) where:
F(e) = The equivalent noise exposure factor.
T = The period of noise exposure at any essentially constant level.
L = The duration of the permissible noise exposure at the constant level (from Table D-2).
If the value of F(e) exceeds unity (1) the exposure exceeds permissible levels.
1926.52(d)(2)(iii)
A sample computation showing an application of the
formula in paragraph (d)(2)(ii) of this section is as follows. An
employee is exposed at these levels for these periods:
110 db A 1/4 hour.
100 db A 1/2 hour.
90 db A 1 1/2 hours.
F(e) = (1/4 divided by 1/2)+(1/2 divided by 2)+(1 1/2 divided by 8)
F(e) = 0.500+0.25+0.188
F(e) = 0.938
Since the value of F(e) does not exceed unity, the exposure is within permissible limits.
1926.52(e)
Exposure to impulsive or impact noise should not
exceed 140 dB peak sound pressure level.
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