TLVs are often compared to other exposure limits such as the Permissible Exposure Limits (PELs) set by the Occupational Safety and Health Administration (OSHA) and Recommended Exposure Limits (RELs) by the National Institute for Occupational Safety and Health (NIOSH). While TLVs are guidelines and not legally enforceable, PELs are regulatory limits and legally binding. RELs are similar to TLVs but are recommendations rather than regulations.
