As I have said, this is all about the “environmental movement” to reduce the regulatory burdens on flammable refrigerants and not about worker safety! You can read OSHA’s own words about by they are proposing this change…
OSHA is proposing several changes to the Flammable Gases hazard class (Appendix B.2). Most significantly, OSHA is proposing to subdivide Category 1 of this class into two subcategories, 1A and 1B, and to specify that pyrophoric gases and chemically unstable gases are to be classified as Category 1A. These proposed changes would provide more detailed information about the flammable gas hazards and track changes made in the GHS Rev. 7 (UN GHS, 2017, Document ID 0060) since OSHA updated the HCS in 2012. These proposed changes would allow downstream users to have a better understanding of the severity of the hazards associated with flammable gases.