Hearing Conservation & Monitoring

OSHA Requirements - When information indicates that any employee's noise exposure equals or exceeds an 8-hour time-weighted average of 85 dBA, the employer must use feasible administrative or engineering controls to reduce noise levels to within OSHA limits. In the event that such controls fail, the employer must establish for effected employees a:

• Hearing Conservation Program - administration of baseline and annual audiograms, as well as the provision of suitable hearing protectors.
• Monitoring Program - measurement of noise levels in work areas to identify employees for inclusion in conservation program and to enable proper selection of hearing protectors. Re measurement of noise levels whenever a change occurs in production, process, equipment or controls that increases employee noise exposure.

NIOSH Recommendations - The National Institute of Occupational Safety and Health (NOISH) has recommended changes to the current OSHA exposure limits. NOISH is responsible for recommending occupational safety and health standards to OSHA for enactment. The primary change is to the lower maximum noise level for 8 hour exposure from 90 dBA to 85 dBA. This change lowers the risk of developing occupational NIHL over a 40-year lifetime exposure from 25% to 8%.

Another important aspect of these recommendations is to stipulate a noise reduction rating (NNR) factor of 25%, 50%, and 70% for earmuffs, formable earplugs, and all other earplugs, respectively. OSHA's current derating is 50% of the manufacturer's stated noise reduction.