OSHA Occupational Noise Regulations - 1910.95
The OSHA noise exposure standards define two action levels at which
worker protection must be provided and used. These actions are based
on the 8-hour Time Weighted Average (TWA) of the noise levels that the
worker is exposed to throughout the working day:
|
|
|
|
|
|
| |
TWA |
Dose |
Action |
Details |
|
|
|
|
|
|
|
| |
85 dBA + |
50% + |
Hearing Conservation Program |
Provide hearing protection for workers to wear if they choose
to.
Give
training on the risks of high noise exposure.
Monitor the levels regularly in case they increase. |
|
|
|
|
|
|
|
| |
90 dBA + |
100% + |
Noise Control Program |
Provide hearing protection, which must be worn.
Provide training on the risks of high levels and the wearing of protection.
Provide audiometric testing. |
|
|
|
|
|
|
|
When noise levels are particularly high (say > 95 dBA) you should
also check that the hearing protection that you are providing is adequate.
A number of methods are available and the most accurate requires the
use of a meter with Octave Band Filters.
Time Weighted Average - TWA - Noise Levels
These noise exposure limits are not based on instantaneous sound
levels. They are based on the TWA (time
weighted average) or Dose %, which indicates the average noise
levels that the worker is exposed to throughout a working day. |
|
TWA
Calculator |
The two most common ways to find out a workers TWA are:
 |
1. Sound Level Meter - Manual Measurements
- Measure the sound levels at the different times of day and
different locations that the worker usually visits.
- Find out how long the worker spends at each location
- Calculate the TWA. See TWA
Calculator.
If a worker stays at just one or two locations with constant noise
levels then this is a relatively easy task. |
| |
|
 |
2. Use a Noise Dosimeter
- Fit the Noise Dosimeter to the worker at the start of the working
day.
- Remove the dosimeter at the end of the day and read off the
TWA or Dose % figure.
The dosimeter approach is much easier when a worker moves between
different locations or the noise levels are changing all the time. |
When to Monitor the Noise Levels
The noise levels in a work place should be carefully monitored using
the correct grade of equipment if there is any possibility that a worker
will be exposed and an 8 hour time weighted average noise level of 85
dB(A) or above. This monitoring should be repeated periodically (e.g. every
year or every two years) or whenever there is change to machinery, production
levels or processes that may impact on the noise levels.
Which Sound Level Meter or Noise Dosimeter?
To be sure of getting accurate and repeatable noise measurements that
can be used for protecting workers' hearing and protecting your company
from legal claims, you should use the correct grade of sound level meter.
The OSHA regulations recommend the use of a Type 2 sound level meter
(you can also use Type 1 as it is more accurate) with "Slow" time weighting.
You should also use a Sound Level Calibrator to check that the meter
is operating correctly before making important measurements. Here are
some suggestions:
|
|
|
|
| |
 |
CR306 Type 2 Sound Level Meter
Ideal for quick measurements, from which you can calculate a worker's
TWA.
Recommended: CK306 Noise Measurement (includes
the meter and a Calibrator) - $1019.00 |
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
 |
CR152A Sound Level Meter
Includes all the measurements for a basic occupational noise survey.
Option for data logging.
Recommended: SC152A Sound Level Meter and Calibrator : $1831.00 |
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
 |
doseBadge Logging Noise Dosimeter
Mounts on the worker's shoulder and monitors the noise levels throughout
the day.
Recommended: CK110/5 Noise Dosimeter Kit (includes
5 dosimeters, Calibrator and accessories) - $6943.00 |
|
|
|
|
|
|
