Understanding Hearing Conservation Standards 1910.95(c)(1) The employer shall administer a continuing, effective hearing conservation program, whenever employee noise exposures equal or exceed an 8-hour time-weighted average sound level of 85 decibels measured on the A scale (slow response) or, equivalently, a dose of fifty percent. The National Institute of Health reports that 36 million Americans, 17% of the population, have some degree of hearing loss. And according to the Bureau of Labor Statistics, for people working in the manufacturing sector, occupational hearing loss is the most commonly recorded occupational health issue. There are an estimated 16 million people working in the manufacturing sector, which accounts for approximately 13% of the U.S. workforce. According to the Bureau of Labor Statistics, occupational hearing loss is the most commonly recorded occupational illness in manufacturing (17,700 cases out of 59,100 cases), accounting for 1-in-9 recordable illnesses. More than 72% of these occur among workers in manufacturing. Three facts • More than 30 million Americans are exposed to hazardous sound levels on a regular basis. • About 26 million 20- to 70-year-olds have experienced hearing loss due to noise exposure. • More than 5 million 16- to 19-year olds have hearing loss due to noise exposure. Terms NRR Noise Reduction Rating TWA Time-Weighted Average dB Decibels OSHA – Occupational noise exposure 1910.95 external icon OSHA sets legal limits on noise exposure in the workplace. These limits are based on a worker’s time-weighted average over an 8-hour day. With noise, OSHA’s permissible exposure limit (PEL) is 90 dBA for all workers for an 8-hour day. Occupational standards specify a maximum allowable daily noise dose, expressed in percentages. For example, a person exposed to 85 dBA per NIOSH or 90 dBA per OSHA over an 8-hour work shift, will reach 100% of their daily noise dose. The noise dose is based on both the sound exposure level and how long it lasts (duration). So for each increase of 3-dB (NIOSH) or 5-dB (OSHA) in noise levels, the duration of the exposure should be cut in half. (This is what’s referred to as exchange rates in standards.) The following table illustrates the relationship between sound exposure levels and durations for both NIOSH and OSHA. SAFETY FOR TECHNICAL SUPPORT CONTACT: SAFETYQUESTIONS@FASTENAL.COM OR 1-833-FNL-SAFE
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