Potential Hazardous Noise is exposure to steady-state noise having an 8-hour TWA noise level above what?

Potential Hazardous Noise is exposure to steady-state noise having an 8-hour TWA noise level above what?

• A. 90 dBA
• B. 85 dBA
• C. 80 dBA
• D. 95 dBA

Answer: (B)

In noise regulation, there’s a specific point at which exposure is flagged for action: an 8-hour time-weighted average that exceeds 85 dBA is considered potential hazardous noise. This threshold is used to trigger hearing conservation measures—monitoring, engineering controls, hearing protection, and audiometric testing—before hearing loss can occur. The 90 dBA level is the permissible exposure limit (PEL) for unprotected exposure, but it’s not the trigger for initiating a full program. An 8-hour TWA of 80 dBA is below the action level, so it wouldn’t require those protections, while 95 dBA is well above the limit and would demand strict controls. Therefore, 85 dBA is the correct benchmark for potential hazardous noise.

In noise regulation, there’s a specific point at which exposure is flagged for action: an 8-hour time-weighted average that exceeds 85 dBA is considered potential hazardous noise. This threshold is used to trigger hearing conservation measures—monitoring, engineering controls, hearing protection, and audiometric testing—before hearing loss can occur. The 90 dBA level is the permissible exposure limit (PEL) for unprotected exposure, but it’s not the trigger for initiating a full program. An 8-hour TWA of 80 dBA is below the action level, so it wouldn’t require those protections, while 95 dBA is well above the limit and would demand strict controls. Therefore, 85 dBA is the correct benchmark for potential hazardous noise.