The refrigerant in this accident is R-32 (), described as ” a colorless, odorless, mildly flammable gas. “Its ASHRAE rating is A2L, making it a CAT1B flammable gas if OSHA adopts Rev. 7 of the GHS this year.
These A2L “mildly flammable gases” are exempt from many of the requirements other flammable gases must meet (e.g., electrical classifications, mechanical exhaust ventilation, gas detection, etc.).
R-32 Info Source: https://www.superradiatorcoils.com/blog/refrigerant-focus-r-32-difluoromethane