On May 6, 2021, the Environmental Protection Agency (EPA) published a Final Rule listing R‒452B, R‒454A, R‒454B, R‒454C, and R‒457A as acceptable substitutes, subject to use conditions, for use in residential and light commercial air conditioning and heat pumps. These refrigerants are flammable and are classified as belonging to ANSI/ASHRAE Standard 34 safety group A2L. The listed substitutes are refrigerant blends; Section 6.1.3 of the ANSI/ASHRAE Standard 34 requires the LFL of refrigerant blends to be measured at 73.4 °F [23.0 °C] and 14.7 psia [101.3 kPa]. These refrigerant blends meet the definition of a Category 1 flammable gas in Section 1910.119(a)(1)(ii).
In the manufacturing plant, after assembly of the mechanical components, refrigerant is charged to an air conditioner or heat pump. These pre-charged pieces of air conditioners and heat pumps are then stored in a warehouse or a distribution center before shipment to customers. Such pieces of pre-charged air conditioners and heat pumps are unconnected but co-located.
Question: Is the storage of pre-charged air conditioners and heat pumps in a warehouse or distribution center subject to OSHA’s PSM Standard, 29 CFR § 1910.119, if the aggregate weight of the refrigerant, a flammable gas, in the stored pre-charged equipment on the premises exceeds the threshold quantity (TQ) of 10,000 pounds?
Response: Yes. For the reasons listed below, what you describe is a PSM-covered process.