[Code of Federal Regulations]
[Title 29, Volume 8]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 29CFR1926.52]
[Page 29]
TITLE 29--LABOR
CHAPTER XVII--OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT
OF LABOR
PART 1926_SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION--Table of Contents
Subpart D_Occupational Health and Environmental Controls
Sec. 1926.52 Occupational noise exposure.
(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.
(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.
(c) If the variations in noise level involve maxima at intervals of
1 second or less, it is to be considered continuous.
(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
------------------------------------------------------------------------
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
------------------------------------------------------------------------
(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.
(ii) F<INF>e</INF> = (T1/L1)+(T2/L2)+ [middot] [middot] [middot] +
(Tn/Ln)
Where:
F<INF>e</INF> = 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<INF>e</INF> exceeds unity (1) the exposure exceeds
permissible levels.
(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<INF>e</INF> = (\1/4\/\1/2\)+(\1/2\/2)+(1\1/2\/8)
F<INF>e</INF> = 0.500+0.25+0.188
F<INF>e</INF> = 0.938
Since the value of F<INF>e</INF> does not exceed unity, the exposure is
within permissible limits.
(e) Exposure to impulsive or impact noise should not exceed 140 dB
peak sound pressure level.
