PDFWAC 296-307-63405

Make sure that noise-measuring equipment meets recognized standards.

(1) The employer must make sure that noise dosimetry equipment meets these specifications:
Dosimeters must be equipment class 2AS-90/80-5 of the American National Rule Specification for Personal Noise Dosimeters, ANSI S1.25-1991, such dosimeters are normally marked "Type 2."
Note:
Make sure any dosimeter used is Type 2 equipment that:
 
1. Uses slow integration and A-weighting of sound levels.
 
2. Has the criterion level set to 90 dB, so the dosimeter will report a constant 8-hour exposure at 90 dBA as a 100% dose.
 
3. Has the threshold level set at 80 dB, so the dosimeter will register all noise above 80 dB.
 
4. Uses a 5 dB exchange rate for averaging of noise levels over the sample period.
(2) The employer must make sure that sound level meters meet these specifications:
(a) American National Standard Specification for Sound Level Meters, S1.4-1984, Type 2 requirements for sound level meters, such sound level meters are normally marked "Type 2."
(b) For continuous noise measurements, the meter must be capable of measuring A-weighted sound levels with slow response.
(c) For impulse or impact noise measurements, the meter must be capable of indicating maximum C-weighted sound level measurements with fast response.
(3) The employer must calibrate dosimeters and sound level meters used to monitor employee noise exposure:
(a) Before and after each day's use;
and
(b) Following the instrument manufacturer's calibration instructions.
Notes:
1. The employer may conduct dosimetry using an exchange rate less than 5 dB and compare the results directly to the noise evaluation criteria in Table 1.
 
2. For measuring impulse and impact noise the employer may also use a sound level meter set to measure maximum impulse C-weighted sound levels or peak C-weighted sound levels.
[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, and 49.17.060. WSR 20-21-091, § 296-307-63405, filed 10/20/20, effective 11/20/20; WSR 05-01-166, § 296-307-63405, filed 12/21/04, effective 4/2/05.]