The State of Occupational Hearing Conservation


New technologies make the goal of OSHA’s Hearing Conservation Amendment, the elimination of noise-induced hearing loss, very feasible.

By Brad Witt, MA, CCC-A  March 1, 2011

OH&S Magazine, Vol. 80 No. 3 

When OSHA enacted its new Hearing Conservation Amendment in 1983, evidence at the time suggested it would be a strong force in eliminating noise-induced hearing loss (NIHL) from the workplace. But nearly 30 years later, reality has shown the high hopes to be unfounded. Occupational hearing loss continues to be called “the most common permanent and preventable occupational injury.”1 And the Bureau of Labor Statistics reports that, despite decades of legislation and intervention by employers, the average number of cases of recordable NIHL in industry has been about 25,000 per year for the past five years.2

The noise hazard remains the same in 2011, but now the landscape for hearing conservation is much different. Technology has fundamentally changed the way we measure the effectiveness of hearing protectors, and several long-awaited changes in regulations appear to be making headway toward enactment. Here is an update of issues and changes that have a major effect on hearing conservation efforts for your noise-exposed workers.

OSHA Rulemaking
At the core of OSHA’s Hearing Conservation Amendment are two numbers: the 90 dB Permissible Exposure Limit (PEL) and the 5 dB Exchange Rate (ER). The PEL is OSHA’s definition of maximum safe noise; any 8-hour exposure exceeding this level requires hearing protection for noise-exposed workers. The Exchange Rate describes the rate at which allowable exposure time is halved; a “5 dB exchange rate” means allowable exposure time is halved for every 5 dB increase in noise levels.

These numbers have their roots in the Walsh-Healey noise regulation of 1969. But the preponderance of scientific evidence since then suggests these levels are far too lax in their protective value. The 90 dB PEL and 5 dB ER still allow a substantial percentage of noise-exposed workers (23 to 32 percent, by NIOSH estimates) to suffer NIHL. This makes workers in the United States far less protected than their counterparts in Europe, Australia, or most other parts of the world.

Reducing the PEL by just 5 decibels (from 90 to 85 dB) would put OSHA in good company. Nearly every country in the world except the United States uses the more-protective 85 dB limit value, and even NIOSH and the U.S. Department of Defense define the 85 dB PEL and 3 dB ER as best practice. Professional organizations including the National Hearing Conservation Association and American Industrial Hygiene Association called upon OSHA last year to reduce the PEL from 90 to 85 dB and adjust the ER from 5 to 3 dB. Most noise dosimeters now allow users to select either 3 or 5 dB exchange rates.

While OSHA has resisted efforts to reopen or update its Hearing Conservation Amendment since its enactment in 1983, there is a growing expectation for a change to be made soon. This is due in part to the fact OSHA may be obligated to update its hearing conservation standard to accommodate a change in the way hearing protectors are rated by the Environmental Protection Agency.

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