Protecting Against Extreme Noise

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Time of issue:2012-12-28 14:11
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Often at noisy facilities, there is one process or area that generates extremely loud noise. It typically is task-specific (such as tank cleaning, motor run-up tests or demolition projects) or tool-specific (a bead blaster, arc welder or jackhammer, for example). All the workers recognize it, even those who work several departments away.

To add to the confusion, hearing experts typically disagree with the regulatory definitions of safe noise. Published noise-dose tables defining safe, time-weighted noise exposures simply fall apart for extreme noise. Using its 5 dB exchange rate and 90 dB criterion level, OSHA¹ defines maximum permissible unprotected noise exposure as 115 dBA for 15 minutes — an overexposure most hearing conservation professionals consider to be unacceptable. In contrast, NIOSH² recommends that no worker be exposed to more than 28 cumulative seconds of noise at 115 dBA (and no other noise) in any workday.

Conventional Method: Dual Protection

Dual protection, using earplugs and earmuffs simultaneously, is sometimes the only available method to achieve maximum protection from hazardous noise. While dual protection typically lengthens the allowable exposure time, it comes at a cost: Using earplugs and earmuffs concurrently significantly can isolate the wearer, making it difficult to communicate or hear warning signals.