On its website, online OSHA itself acknowledges https://www.osha.gov/dsg/annotated-pels/ OSHA's PEL OSHA's PEL several types of exposure limits OSHA’s indoor air levels permissible exposure limit Permissible Exposure Limits (PELs) The Occupational Safety and Health Administration (OSHA) OSHA’s PEL Webpage "OSHA Annotated PELs" OSHA’s website permissible exposure limit OSHA itself acknowledges Annotated Permissible Exposure Limits