What is the permissible exposure level for OSHA and MSHA?

The permissible exposure level established by OSHA (Occupational Safety and Health Administration) for noise exposure in the workplace is set at 90 dBA for an 8-hour time-weighted average. This standard aims to protect workers from the detrimental effects of prolonged noise exposure which can lead to hearing loss.

At this level, employers are required to implement a hearing conservation program if employees are exposed to these levels of noise for over 8 hours. This includes monitoring noise levels, providing hearing protection, and conducting regular hearing tests. The guideline is based on extensive research indicating that noise levels above this threshold can significantly increase the risk of noise-induced hearing loss over time.

MSHA (Mine Safety and Health Administration) also adopts similar exposure limits in various mining environments, reinforcing the importance of maintaining noise exposure at or below this level to ensure the health and safety of workers in those settings. Thus, the choice of 90 dBA reflects the consensus among occupational health standards about protecting workers from excessive noise.