Although the two programs have significant overlap, each has its own focus. PSM is an occupational health program intended to protect workers; RMP is intended to protect the environment and the community. PSM is an OSHA program, whereas RMP is an EPA program.
Another big difference is that RMP (the program) requires development of a RMP (the plan). RMP requires a hazard analysis to estimate the offsite impact due to worst-case and alternate releases. See 40 CFR 68 Subpart B. These analysis shall be updated every five years or within six months of a significant change. See 40 CFR 68.36. The owner or operator must submit a Risk Management Plan (“RMP”) that includes the worst case and alternate release scenarios, a five-year accident history, information concerning the facility emergency response plan, and more. See 40 CFR 68 Part G. Updates of the RMP are required at least every five years, or as circumstances occur that materially affect the regulatory status of the process. Those circumstances are listed at 40 CFR 68.190(b).
Applicability threshold criteria are different for the two programs. For example, the threshold quantity for hydrogen sulfide under PSM is 1500 pounds, whereas under RMP, the threshold is 10,000 pounds. The RMP threshold for ammonia is 20,000 pounds, but only for solutions where the concentration is above 20%; the OSHA threshold for ammonia solutions is 15,000 pounds for solutions with an ammonia concentration above 44%. The RMP applicability list contains some compounds that are not located on the PSM list (e.g., Allyl alcohol); likewise, some compounds that result in PSM applicability, don’t case RMP applicability (Ammonium Perchlorate).
The EPA recently issued a Request for Information (“RFI”) requesting comment on potential revision to the RMP. In this RFI, EPA mentioned other significant, as applied, differences in applicability under PSM and RMP. For example, approximately 4000 bulk chemical distributors claim they are exempt from PSM based on OSHA’s “retail facility” exemption in 29 CFR 1910.19(a)(2)(i). Also, wastewater facilities in states without federally-delegated, state run OSHA programs are generally not subject to PSM requirements. See RFI, pages 59-60 of 113. As a result, these facilities are usually RMP Program 2, whereas the same plant with a federally-delegated OSHA program is RMP Program 3. See RFI, pages 60-61 of 113.