What is the OSHA standard concept of permissible exposure limit (PEL) for noise, and what protection is typically used?

• A. PEL is 80 dBA; action 70; PPE only
• B. PEL is 95 dBA; action 90; PPE not required
• C. PEL for noise is 90 dBA TWA8; action level is 85 dBA; use hearing protection and engineering controls to reduce exposure
• D. PEL is 85 dBA; action level 80; use engineering controls only

Answer: (C)

OSHA sets noise exposure limits based on a time-weighted average over an 8-hour shift. The permissible exposure limit is 90 dBA averaged over 8 hours, and the action level is 85 dBA. When exposures approach or exceed the action level, a hearing conservation plan is typically required, and employers use a combination of engineering controls to lower the noise at the source and hearing protection devices (like earplugs or earmuffs) to reduce the actual exposure for workers. Engineering controls aim to bring the noise down below the PEL, while PPE provides additional protection if further reduction isn’t feasible or as a supplement. This combined approach is why the best answer reflects a PEL of 90 dBA with an action level of 85 dBA and the use of both controls and hearing protection.