Memo - Process Safety Management (PSM) Guidance: Appendix A Threshold Quantities

This memo revised OSHA's enforcement policy on the concentration of a chemical that must be in a process to meet or exceed the threshold quantity (TQ) specified in Appendix A - List of Highly Hazardous Chemicals, Toxics and Reactives (Mandatory) of 29 CFR 1910.119.

Also reference Memo - Recognized And Generally Accepted Good Engineering Practices (RAGAGEP) in Process Safety Management (PSM) Enforcement, CFR 114A - Process Safety Management of Highly Hazardous Chemicals; Final Rule; Administrative Stay, CPL 02-01-065 - Process Safety Management (PSM) of Highly Hazardous Chemicals, CPL 03-00-21, Process Safety Management (PSM) Covered Facilities, and Memo - Process Safety Management (PSM) Retail Exemption Enforcement Policy.

Additional information and resources can be found on the safety and health topic page for Process Safety Management.