The A1 and B1 fluids were those envisioned to be used where flammability was a high concern. The A1, B1, A2 and B2 refrigerants were those contemplated for use in indirect systems, such as those using chillers. This distinction involves an intermediate fluid, heated or cooled by the refrigerant, that in turn heats or cools air in an occupied area through a second heat exchanger or a spray. The probability of a refrigerant entering an occupied area is reduced in case of a leak. The A3 and B3 fluids were those foreseen primarily for industrial uses, when other refrigerants would not be suitable due to unique requirements.
R14 = A1
21 = B1
22 = A1
23 = A1
30 = B2
31 = ....
32 = A2
40 = B2
41 = ....
50 = A3
113 = A1
114 = A1
115 = A1
116 = A1
123 = B1
124 = A1
125 = A1
134a= A1
141b= ....
142b= A2
143a= A2
152a= A2
170 = A3
218 = A1
236fa=A1
245fa=A1
290 = A3
C318= ....
600 = A3
600a= A3
610 = ....
611 = B2
620 = ....
630 = ....
631 = ....
702 = A3
704 = A1
717 = B2
718 = A1
720 = A1
728 = A1
732 = ....
740 = A1
744 = A1
744a= ....
764 = B1
1150 = A3
1270 = A3
400 = A1
401A= A1
401B= A1
401C= A1
402A= A1
402B= A1
403A= A1
404A= A1
405A= ....
406A= A2
407A= A1
407B= A1
407C= A1
407D= A1
407E= A1
408A= A1
409A= A1
409B= A1
410A= A1
410B= A1
411A= A2
411B= A2
412A= A2
413A= A2
414A= A1
500 = A1
501 = A1
502 = A1
NO CLASSIFICATION FOR 503,504, 505 OR 506
507A = A1
508A = A1
508B = A1
509A = A1