Why are NIOSH and OSHA guidelines so different?
The NIOSH and OSHA guidelines were both developed to help protect the hearing of industrial workers. As such, they can only predict average risk across a large population, not individual risk. According to the U.S. Dept of Health and Human Services, the excess risk of developing occupational noise-induced hearing loss (NIHL) is 8% when adhering to the NIOSH guideline and 25% with the OSHA guideline. (Source: NIOSH Publication No.
