One of the top questions I receive is asking about how NFPA 704 ratings play into the application to OSHA’s Process Safety Management standard and EPA’s Risk Management Plan rule. I hope to clarify any confusion this NFPA 704 application may be causing, as YES – the NFPA 704 does have a role in determining if certain MIXTURES fall under the RMP rule. However, this ONLY applies to certain FLAMMABLE MIXTURES and ONLY is used in EPA’s RMP rule – NOT in OSHA’s PSM application. Let me explain …