49 CFR Appendix B to Part 227, Methods for Estimating the Adequacy of Hearing Protector Attenuation
This appendix is mandatory.
Employers must select one of the following three methods by which to estimate the adequacy of hearing protector attenuation.
Derate the hearing protector attenuation by type using the following requirements:
A. Subtract 7 dB from the published Noise Reduction Rating (NRR).
B. Reduce the resulting amount by:
1. 20% for earmuffs,
2. 40% for form-able earplugs, or
3. 60% for all other earplugs.
C. Subtract the remaining amount from the A-weighted TWA. You will have the estimated A-weighted TWA for that hearing protector.
Use Method B, which is found in ANSI S12.6-1997 (Reaffirmed 2002) “Methods for Measuring the Real-Ear Attenuation of Hearing Protectors.” The Director of the Federal Register approves the incorporation by reference of this standard in accordance with 5 U.S.C. 552(a) and 11 CFR part 51. You may obtain a copy of the incorporated standard from the American National Standards Institute at 1819 L Street, NW., Washington, DC 20036, or http://www.ansi.org. You may inspect a copy of the incorporated standard at the Federal Railroad Administration, Docket Room, 1200 New Jersey Avenue, SE., Washington, DC 20590, or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
Use actual measurements of the level of noise exposure (as an A-weighted SLOW response dose) inside the hearing protector when the employee wears the hearing protector in the actual work environment.
Title 49 published on 2015-12-03
The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 49 CFR Part 227 after this date.
Title 49 published on 2015-12-03.
The following are only the Rules published in the Federal Register after the published date of Title 49.
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