Health & Safety Insights

Flammable Liquids and the PSM Requirements

Mitch Lagerstrom - Director of Consulting - EHS Practice

Date: 10/20/2022

Process Safety Management (PSM) is a performance-based, regulatory-required management system designed to protect workers from highly hazardous chemicals (HHC). PSM applies to all companies that deal with any of more than 130 toxic and reactive chemicals in quantities listed in Appendix A of OSHA’s Process Safety Management of Highly Hazardous Chemicals Standard (29 CFR 1910.119).

Flammable liquids are one of the categories of HHC subject to PSM. Specifically, liquids with a flashpoint below 100 °F and a total onsite quantity above 10,000 pounds are subject to the regulation under 29 CFR §1910.119(a)(1)(ii). However, PSM contains an exemption for flammable liquids stored in atmospheric tanks that are kept below their normal boiling point without refrigeration or chilling [29 CFR §1910.119(a)(1)(ii)(B)].

OSHA has further clarified that the atmospheric tank exemption extends to drums storing flammable liquids. This would further extend to other smaller or larger atmospheric containers storing flammable liquids. For example, windshield washer fluid containing methanol with a flashpoint below 100 °F meets the definition of a flammable liquid in the PSM standard, but is exempt from regulation under PSM if it is stored in atmospheric containers, even if the total quantity exceeds 10,000 pounds. Even though it meets an exemption under the PSM regulation, it is still subject to OSHA’s General Duty Clause (GDC).

The Risk Management Plan (RMP) does not contain a provision for flammable liquids. Storage of any of these chemicals below 10,000 pounds are required to be in compliance with the Environmental Protection Agency’s (EPA) RMP GDC. Continuing with the windshield washer example, methanol is not a listed chemical under RMP, however it is regulated as an EHS under EPA’s RMP GDC. EPA includes any HHC listed under PSM as an EHS under the RMP GDC. The agency’s ability to include these substances and any other substance is further clarified in the agency’s GDC guidance discussed below.

Due to the complexity of the requirements and the dangers inherent with flammable liquids, it’s crucial to understand how to keep your company in compliance.