2011 ASHRAE Refrigerant Safety Standards
ASHRAE has published its 2010 editions of Refrigerant Safety Standards. In these editions, HFO-1234yf and 14 refrigerant blends have been added. An optional 2L flammability classification subclass has been added to the existing Class 2 category, addressing refrigerants with a burning velocity less than or equal to 10 cm/s, such as HFOs, and a modified method of calculating the heat of combustion for refrigerants introduced. Occupational exposure limits for refrigerants, new data and updates of refrigerant concentration limits (RCL) and safety classifications for several existing refrigerants have been added.