1127.1 General — 2025 California Mechanical Code

Cooling towers, evaporative coolers and fluid coolers shall be provided with an approved water supply, sized for peak demand. The quality of water shall be provided in accordance with the equipment manufacturer’s recommendations. The piping system and protection of the potable water supply system shall be installed in accordance with the plumbing code.

248 2025 CALIFORNIA MECHANICAL CODE

REFRIGERATION

TABLE 1102.3 REFRIGERANT GROUPS, PROPERTIES, AND ALLOWABLE QUANTITIES [7]

[ASHRAE 34: TABLE 4-1, TABLE 4-2]

REFRIGERANT	CHEMICAL FORMULA	CHEMICAL NAME1 (COMPOSITION FOR BLENDS)	SAFETY GROUP	OEL2 (ppm)	RCL (lb/Mcf)	LFL8 (lb/Mcf)
R-11	CCl3F	Trichlorofluoromethane	A1	1000	0.39	––
R-12	CCl2F2	Dichlorodifluoromethane	A1	1000	5.6	––
R-12B1	CBrClF2	Bromochlorodifluoromethane	––	––	––	––
R-13	CClF3	Chlorotrifluoromethane	A1	1000	––	––
R-13B1	CBrF3	Bromotrifluoromethane	A1	1000	––	––
R-13I1	CF3I	Trifluoroiodomethane	A1	500	1.0	––
R-14	CF4	Tetrafluoromethane (carbon tetrafluoride)	A1	1000	25	––
R-21	CHCl2F	Dichlorofluoromethane	B1	––	––	––
R-22	CHClF2	Chlorodifluoromethane	A1	1000	13	––
R-23	CHF3	Trifluoromethane	A1	1000	7.3	––
R-30	CH2Cl2	Dichloromethane (methylene chloride)	B1	––	––	––
R-31	CH2ClF	Chlorofluoromethane	––	––	––	––
R-32	CH2F2	Difluoromethane (methylene fluoride)	A2L	1000	4.8	19.1
R-40	CH3Cl	Chloromethane (methyl chloride)	B2	––	––	––
R-41	CH3F	Fluoromethane (methyl fluoride)	––	––	––	––
R-50	CH4	Methane	A3	1000	––	––
R-113	CCl2FCClF2	1, 1, 2-trichloro-1, 2, 2-trifluoroethane	A1	1000	1.2	––
R-114	CClF2CClF2	1, 2-dichloro-1, 1, 2, 2-tetrafluoroethane	A1	1000	8.7	––
R-115	CClF2CF3	Chloropentafluoroethane	A1	1000	47	––
R-116	CF3CF3	Hexafluoroethane	A1	1000	34	––
R-123	CHCl2CF3	2, 2-dichloro-1, 1, 1-trifluoroethane	B1	50	3.5	––
R-124	CHClFCF3	2-chloro-1, 1, 1, 2-tetrafluoroethane	A1	1000	3.5	––
R-125	CHF2CF3	Pentafluoroethane	A1	1000	23	––
R-134a	CH2FCF3	1, 1, 1, 2-tetrafluoroethane	A1	1000	13	––
R-141b	CH3CCl2F	1, 1-dichloro-1-fluoroethane	––	500	0.78	17.8
R-142b	CH3CClF2	1-chloro-1, 1-difluoroethane	A2	1000	5.1	20.4
R-143a	CH3CF3	1, 1, 1-trifluoroethane	A2L	1000	4.4	17.5
R-152a	CH3CHF2	1, 1-difluoroethane	A2	1000	2.0	8.1
R-170	CH3CH3	Ethane	A3	1000	0.54	2.4
R-E170	CH3OCH3	Methoxymethane (Dimethyl ether)	A3	1000	1.0	4.0
R-218	CF3CF2CF3	Octafluoropropane	A1	1000	43	––
R-227ea	CF3CHFCF3	1, 1, 1, 2, 3, 3, 3-heptafluoropropane	A1	1000	36	––
R-236fa	CF3CH2CF3	1, 1, 1, 3, 3, 3-hexafluoropropane	A1	1000	21	––
R-245fa	CHF2CH2CF3	1, 1, 1, 3, 3-pentafluoropropane	B1	300	12	––
R-290	CH3CH2CH3	Propane	A3	1000	0.59	2.4
R-C318	-(CF2)4-	Octafluorocyclobutane	A1	1000	41	––
R-400	zeotrope	R-12/114 (50.0/50.0)	A1	1000	10	––
R-400	zeotrope	R-12/114 (60.0/40.0)	A1	1000	11	––
R-401A	zeotrope	R-22/152a/124 (53.0/13.0/34.0)	A1	1000	6.6	––

REFRIGERATION

TABLE 1102.3 (continued) REFRIGERANT GROUPS, PROPERTIES, AND ALLOWABLE QUANTITIES [7]

[ASHRAE 34: TABLE 4-1, TABLE 4-2]

REFRIGERANT	CHEMICAL FORMULA	CHEMICAL NAME1 (COMPOSITION FOR BLENDS)	SAFETY GROUP	OEL2 (ppm)	RCL (lb/Mcf)	LFL8 (lb/Mcf)
R-401B	zeotrope	R-22/152a/124 (61.0/11.0/28.0)	A1	1000	7.2	––
R-401C	zeotrope	R-22/152a/124 (33.0/15.0/52.0)	A1	1000	5.2	––
R-402A	zeotrope	R-125/290/22 (60.0/2.0/38.0)	A1	1000	17	––
R-402B	zeotrope	R-125/290/22 (38.0/2.0/60.0)	A1	1000	15	––
R-403A	zeotrope	R-290/22/218 (5.0/75.0/20.0)	A2	1000	7.6	––
R-403B	zeotrope	R-290/22/218 (5.0/56.0/39.0)	A1	1000	18	––
R-404A	zeotrope	R-125/143a/134a (44.0/52.0/4.0)	A1	1000	31	––
R-405A	zeotrope	R-22/152a/142b/C318 (45.0/7.0/5.5/42.5)	––	1000	16	––
R-406A	zeotrope	R-22/600a/142b (55.0/4.0/41.0)	A2	1000	4.7	18.8
R-407A	zeotrope	R-32/125/134a (20.0/40.0/40.0)	A1	1000	19	––
R-407B	zeotrope	R-32/125/134a (10.0/70.0/20.0)	A1	1000	21	––
R-407C	zeotrope	R-32/125/134a (23.0/25.0/52.0)	A1	1000	18	––
R-407D	zeotrope	R-32/125/134a (15.0/15.0/70.0)	A1	1000	16	––
R-407E	zeotrope	R-32/125/134a (25.0/15.0/60.0)	A1	1000	17	––
R-407F	zeotrope	R-32/125/134a (30.0/30.0/40.0)	A1	1000	20	––
R-407G	zeotrope	R-32/125/134a (2.5/2.5/95.0)	A1	1000	13	––
R-407H	zeotrope	R-32/125/134a (32.5/15.0/52.5)	A1	1000	19	––
R-407I	zeotrope	R-32/125/124a (19.5/8.5/72.0)	A1	1000	16	––
R-408A	zeotrope	R-125/143a/22 (7.0/46.0/47.0)	A1	1000	21	––
R-409A	zeotrope	R-22/124/142b (60.0/25.0/15.0)	A1	1000	7.1	––
R-409B	zeotrope	R-22/124/142b (65.0/25.0/10.0)	A1	1000	7.3	––
R-410A	zeotrope	R-32/125 (50.0/50.0)	A1	1000	26	––
R-410B	zeotrope	R-32/125 (45.0/55.0)	A1	1000	27	––
R-411A6	zeotrope	R-1270/22/152a (1.5/87.5/11.0)	A2	970	2.9	11.6
R-411B6	zeotrope	R-1270/22/152a (3.0/94.0/3.0)	A2	940	2.8	14.8
R-412A	zeotrope	R-22/218/142b (70.0/5.0/25.0)	A2	1000	5.1	20.5
R-413A	zeotrope	R-218/134a/600a (9.0/88.0/3.0)	A2	1000	5.8	23.4
R-414A	zeotrope	R-22/124/600a/142b (51.0/28.5/4.0/16.5)	A1	1000	6.4	––
R-414B	zeotrope	R-22/124/600a/142b (50.0/39.0/1.5/9.5)	A1	1000	6.0	––
R-415A	zeotrope	R-22/152a (82.0/18.0)	A2	1000	2.9	11.710
R-415B	zeotrope	R-22/152a (25.0/75.0)	A2	1000	2.1	8.4
R-416A6	zeotrope	R-134a/124/600 (59.0/39.5/1.5)	A1	1000	3.9	––
R-417A6	zeotrope	R-125/134a/600 (46.6/50.0/3.4)	A1	1000	3.5	––
R-417B	zeotrope	R-125/134a/600 (79.0/18.3/2.7)	A1	1000	4.3	––
R-417C	zeotrope	R-125/134a/600 (19.5/78.8/1.7)	A1	1000	5.4	––
R-418A	zeotrope	R-290/22/152a (1.5/96.0/2.5)	A2	1000	4.8	19.210
R-419A	zeotrope	R-125/134a/E170 (77.0/19.0/4.0)	A2	1000	4.2	16.710
R-419B	zeotrope	R-125/134a/E170 (48.5/48.0/3.5)	A2	1000	4.6	18.510
R-420A	zeotrope	R-134a/142b (88.0/12.0)	A1	1000	12	––
R-421A	zeotrope	R-125/134a (58.0/42.0)	A1	1000	17	––
R-421B	zeotrope	R-125/134a (85.0/15.0)	A1	1000	21	––
R-422A	zeotrope	R-125/134a/600a (85.1/11.5/3.4)	A1	1000	18	––
R-422B	zeotrope	R-125/134a/600a (55.0/42.0/3.0)	A1	1000	16	––
R-422C	zeotrope	R-125/134a/600a (82.0/15.0/3.0)	A1	1000	18	––
R-422D	zeotrope	R-125/134a/600a (65.1/31.5/3.4)	A1	1000	16	––
R-422E	zeotrope	R-125/134a/600a (58.0/39.3/2.7)	A1	1000	16	––

250 2025 CALIFORNIA MECHANICAL CODE

REFRIGERATION

TABLE 1102.3 (continued) REFRIGERANT GROUPS, PROPERTIES, AND ALLOWABLE QUANTITIES [7]

[ASHRAE 34: TABLE 4-1, TABLE 4-2]

REFRIGERANT	CHEMICAL FORMULA	CHEMICAL NAME1 (COMPOSITION FOR BLENDS)	SAFETY GROUP	OEL2 (ppm)	RCL (lb/Mcf)	LFL8 (lb/Mcf)
R-423A	zeotrope	R-134a/227ea (52.5/47.5)	A1	1000	19	––
R-424A6	zeotrope	R-125/134a/600a/600/601a (50.5/47.0/0.9/1.0/0.6)	A1	990	6.2	––
R-425A	zeotrope	R-32/134a/227ea (18.5/69.5/12.0)	A1	1000	16	––
R-426A6	zeotrope	R-125/134a/600/601a (5.1/93.0/1.3/0.6)	A1	990	5.2	––
R427A	zeotrope	R-32/125/143a/134a (15.0/25.0/10.0/50.0)	A1	1000	18	––
R428A	zeotrope	R-125/143a/290/600a (77.5/20.0/0.6/1.9)	A1	1000	23	––
R-429A	zeotrope	R-E170/152a/600a (60.0/10.0/30.0)	A3	1000	0.81	3.2
R-430A	zeotrope	R-152a/600a (76.0/24.0)	A3	1000	1.3	5.2
R-431A	zeotrope	R-290/152a (71.0/29.0)	A3	1000	0.68	2.7
R-432A	zeotrope	R-1270/E170 (80.0/20.0)	A3	550	0.13	2.4
R-433A	zeotrope	R-1270/290 (30.0/70.0)	A3	760	0.34	2.4
R-433B	zeotrope	R-1270/290 (5.0/95.0)	A3	950	0.39	2.0
R-433C	zeotrope	R-1270/290 (25.0/75.0)	A3	790	0.41	2.0
R-434A	zeotrope	R-125/143a/134a/600a (63.2/18.0/16.0/2.8)	A1	1000	20	––
R-435A	zeotrope	R-E170/152a (80.0/20.0)	A3	1000	1.1	4.3
R-436A	zeotrope	R-290/600a (56.0/44.0)	A3	1000	0.50	2.0
R-436B	zeotrope	R-290/600a (52.0/48.0)	A3	1000	0.51	2.0
R-436C	zeotrope	R-290/600a (95.0/5.0)	A3	1000	0.57	2.3
R-437A	zeotrope	R-125/134a/600/601 (19.5/78.5/1.4/0.6)	A1	990	5.1	––
R-438A	zeotrope	R-32/125/134a/600/601a (8.5/45.0/44.2/1.7/0.6)	A1	990	4.9	––
R-439A	zeotrope	R-32/125/600a (50.0/47.0/3.0)	A2	1000	4.7	18.9
R-440A	zeotrope	R-290/134a/152a (0.6/1.6/97.8)	A2	1000	1.9	7.811
R-441A	zeotrope	R-170/290/600a/600 (3.1/54.8/6.0/36.1)	A3	1000	0.39	2.0
R-442A	zeotrope	R-32/125/134a/152a/227ea (31.0/31.0/30.0/3.0/5.0)	A1	1000	21	––
R-443A	zeotrope	R-1270/290/600a (55.0/40.0/5.0)	A3	640	0.19	2.2
R-444A	zeotrope	R-32/152a/1234ze(E) (12.0/5.0/83.0)	A2L	850	5.1	19.9
R-444B	zeotrope	R-32/152a/1234ze(E) (41.5/10.0/48.5)	A2L	930	4.3	17.3
R-445A	zeotrope	R-744/134a/1234ze (E) (6.0/9.0/85.0)	A2L	930	4.2	2.7
R-446A	zeotrope	R-32/1234ze(E)/600 (68.0/29.0/3.0)	A2L	960	2.5	13.510
R-447A	zeotrope	R-32/125/1234ze(E) (68.0/3.5/28.5)	A2L	960	2.6	18.910
R-447B	zeotrope	R-32/125/1234ze(E) (68.0/8.0/24.0)	A2L	970	2.6	20.6
R-448A	zeotrope	R-32/125/1234yf/134a/1234ze(E) (26.0/26.0/20.0/21.0/7.0)	A1	860	24	––
R-448B	––	R-32/125/1234yf/134a/1234ze(E) (21.0/21.0/20.0/31.0/7.0)	A1	850	22.0	––
R-449A	zeotrope	R-32 /125 /1234yf /134a (24.3/24.7/25.3/25.7)	A1	840	23	––
R-449B	zeotrope	R-32/125/1234yf/134a (25.2/24.3/23.2/27.3)	A1	850	23	––
R-449C	zeotrope	R-32/125/1234yf/134a (20.0/20.0/31.0/29.0)	A1	800	23	––
R-450A	zeotrope	R-134a/1234ze(E) (42.0/58.0)	A1	880	20	––

REFRIGERATION

TABLE 1102.3 (continued) REFRIGERANT GROUPS, PROPERTIES, AND ALLOWABLE QUANTITIES [7]

[ASHRAE 34: TABLE 4-1, TABLE 4-2]

REFRIGERANT	CHEMICAL FORMULA	CHEMICAL NAME1 (COMPOSITION FOR BLENDS)	SAFETY GROUP	OEL2 (ppm)	RCL (lb/Mcf)	LFL8 (lb/Mcf)
R-451A	zeotrope	R-1234yf/134a (89.8/10.2)	A2L	530	5.0	20.310
R-451B	zeotrope	R-1234yf/134a (88.8/11.2)	A2L	530	5.0	20.310
R-452A	zeotrope	R-32/125/1234yf (11.0/59.0/30.0)	A1	790	27	––
R-452B	zeotrope	R-32/125/1234yf (67.0/7.0/26.0)	A2L	870	4.8	19.3
R-452C	zeotrope	R-32/125/1234yf (12.5/61.0/26.5)	A1	810	27	––
R-453A	zeotrope	R-32/125/134a/227ea/600/601a (20.0/20.0/53.8/5.0/0.6/0.6)	A1	1000	7.8	––
R-454A	zeotrope	R-32/1234yf (35.0/65.0)	A2L	690	3.2	18.310
R-454B	zeotrope	R-32/1234yf (68.9/31.1)	A2L	850	3.1	22.010
R-454C	zeotrope	R-32/1234yf (21.5/78.5)	A2L	620	4.4	18.010
R-455A	zeotrope	R-744/32/1234yf (3.0/21.5/75.5)	A2L	650	4.9	26.9
R-456A	zeotrope	R-32/134a/1234ze(E) (6.0/45.0/49.0)	A1	900	20	––
R-457A	zeotrope	R-32/1234yf/152a (18.0/70.0/12.0)	A2L	650	3.4	13.5
R-457B	zeotrope	R-32/1234yf/152a (35.0/55.0/10.0)	A2L	730	3.7	14.9
R-458A	zeotrope	R-32/125/134a/227ea/236fa (20.5/4.0/61.4/13.5/0.6)	A1	1000	18	––
R-459A	zeotrope	R-32/1234yf/1234ze(E) (68.0/26.0/6.0)	A2L	870	4.3	17.4
R-459B	zeotrope	R-32/1234yf/1234ze(E) (21.0/69.0/10.0)	A2L	640	5.8	23.3
R-460A	zeotrope	R-32/125/134a/1234ze(E) (12.0/52.0/14.0/22.0)	A1	950	24	––
R-460B	zeotrope	R-32/125/134a/1234ze(E) (28.0/25.0/20.0/27.0)	A1	950	25	––
R-460C	zeotrope	R-32/125/134a/1234ze(E) (2.5/2.5/46.0/49.0)	A1	900	20	––
R-461A	zeotrope	R-125/143a/134a/227ea/600a (55.0/5.0/32.0/5.0/3.0)	A1	1000	17	––
R-462A	zeotrope	R-32/125/143a/134a/600 (9.0/42.0/2.0/44.0/3.0)	A2	1000	3.9	16.69
R-463A	zeotrope	R-744/32/125/1234yf/134a (6.0/36.0/30.0/14.0/14.0)	A1	990	19	––
R-464A	zeotrope	R-32/125/1234ze(E)/227ea (27.0/27.0/40.0/6.0)	A1	930	27	––
R-465A	zeotrope	R-32/290/1234yf (21.0/7.9/71.1)	A2	660	2.5	10.0
R-466A	zeotrope	R-32/125/13I1 (49.0/11.5/39.5)	A1	860	6.2	––
R-467A	zeotrope	R-32/125/134a/600a (22.0/5.0/72.4/0.6)	A2L	1000	6.7	––
R-468A	zeotrope	R-1132a/32/1234yf (3.5/21.5/75.0)	A2L	610	4.1	––
R-468B	––	R-1132a/32/1234yf (6.0/13.0/81.0)	A2L	570	4.4	––
R-468C	––	R-1132a/32/1234yf (6.0/42.0/52.0)	A2L	710	4.3	––
R-469A	zeotrope	R-744/R-32/R-125 (35.0/32.5/32.5)	A1	1600	8	––
R-470A	zeotrope	R-744/32/125/134a/1234ze(E)/227ea (10.0/17.0/19.0/7.0/44.0/3.0)	A1	1100	17	––
R-470B	zeotrope	R-744/32/125/134a/1234ze(E)/227ea (10.0/11.5/11.5/3.0/57.0/7.0)	A1	1100	16	––
R-471A	zeotrope	R-1234ze(E)/227ea/1336mzz(E) (78.7/4.3/17.0)	A1	710	9.7	––

252 2025 CALIFORNIA MECHANICAL CODE

REFRIGERATION

TABLE 1102.3 (continued) REFRIGERANT GROUPS, PROPERTIES, AND ALLOWABLE QUANTITIES [7]

[ASHRAE 34: TABLE 4-1, TABLE 4-2]

REFRIGERANT	CHEMICAL FORMULA	CHEMICAL NAME1 (COMPOSITION FOR BLENDS)	SAFETY GROUP	OEL2 (ppm)	RCL (lb/Mcf)	LFL8 (lb/Mcf)
R-472A	zeotrope	R-744/32/134a (69.0/12.0/19.0)	A1	2700	4.5	––
R-472B	––	R-744/32/134a (58.0/10.0/32.0)	A1	2400	5.0	––
R-472C	––	R-32/125/143a/134a (25.0/25.0/10.0/40.0)	A1	1000	20.0	––
R-473A	––	R-1132a/23/744/125 20.0/10.0/60.0/10.0)	A1	1700	4.8	––
R-475A	––	R-1234yf/134a/1234ze(E) (45.0/43.0/12.0)	A1	690	20.0	––
R-500	azeotrope3	R-12/152a (73.8/26.2)	A1	1000	7.4	––
R-501	azeotrope3	R-22/12 (75.0/25.0)4	A1	1000	13	––
R-502	azeotrope3	R-22/115 (48.8/51.2)	A1	1000	21	––
R-503	azeotrope3	R-23/13 (40.1/59.9)	––	1000	––	––
R-504	azeotrope3	R-32/115 (48.2/51.8)	––	1000	28	––
R-505	azeotrope3	R-12/31 (78.0/22.0)4	––	––	––	––
R-506	azeotrope3	R-31/114 (55.1/44.9)	––	––	––	––
R-507A5	azeotrope3	R-125/143a (50.0/50.0)	A1	1000	32	––
R-508A5	azeotrope3	R-23/116 (39.0/61.0)	A1	1000	14	––
R-508B	azeotrope3	R-23/116 (46.0/54.0)	A1	1000	13	––
R-509A5	azeotrope3	R-22/218 (44.0/56.0)	A1	1000	24	––
R-510A	azeotrope3	R-E170/600a (88.0/12.0)	A3	1000	0.87	3.5
R-511A	azeotrope3	R-290/E170 (95.0/5.0)	A3	1000	0.59	2.4
R-512A	azeotrope3	R-134a/152a (5.0/95.0)	A2	1000	1.9	7.7
R-513A	azeotrope3	R-1234yf/134a (56.0/44.0)	A1	650	20	––
R-513B	azeotrope3	R-1234yf/134a (58.5/41.5)	A1	640	21	––
R-514A	azeotrope3	R-1336mzz(Z)/1130 (E) (74.7/25.3)	B1	320	0.86	––
R-515A	azeotrope3	R-1234ze(E)/227ea (88.0/12.0)	A1	810	19	––
R-515B	azeotrope3	R-1234ze(E)/227ea (91.1/8.9)	A1	810	18	––
R-516A	azeotrope3	R-1234yf/134a/152a (77.5/8.5/14.0)	A2L	590	3.2	13.1
R-600	CH3CH2CH2CH3	Butane	A3	1000	0.15	3.0
R-600a	CH(CH3)2CH3	2-methylpropane (isobutene)	A3	1000	0.59	2.4
R-601	CH3CH2CH2CH2 CH3	Pentane	A3	600	0.18	2.2
R-601a	(CH3)2CHCH2CH3	2-methylbutane (isopentane)	A3	600	0.18	2.4
R-610	CH3CH2OCH2CH3	Ethoxyethane (ethyl ether)	––	400	––	––
R-611	HCOOCH3	Methyl formate	B2	100	––	––
R-620	––	(Reserved for future assignment)	––	––	––	––
R-630	CH3NH2	Methanamine (methyl amine)	––	––	––	––
R-631	CH3CH2(NH2)	Ethanamine (ethyl amine)	––	––	––	––
R-702	H2	Hydrogen	A3	––	––	––
R-704	He	Helium	A1	––	––	––
R-717	NH3	Ammonia	B2L	25	0.014	7.2
R-718	H2O	Water	A1	––	––	––
R-720	Ne	Neon	A1	––	––	––
R-728	N2	Nitrogen	A1	––	––	––

REFRIGERATION

TABLE 1102.3 (continued) REFRIGERANT GROUPS, PROPERTIES, AND ALLOWABLE QUANTITIES [7]

[ASHRAE 34: TABLE 4-1, TABLE 4-2]

REFRIGERANT	CHEMICAL FORMULA	CHEMICAL NAME1 (COMPOSITION FOR BLENDS)	SAFETY GROUP	OEL2 (ppm)	RCL (lb/Mcf)	LFL8 (lb/Mcf)
R-732	O2	Oxygen	––	––	––	––
R-740	Ar	Argon	A1	––	––	––
R-744	CO2	Carbon dioxide	A1	5000	3.4	––
R-744A	N2O	Nitrous oxide	––	––	––	––
R-764	SO2	Sulfur dioxide	B1	––	––	––
R-1130(E)	CHCl=CHCl	Trans-1,2-dichloroethene	B2	200	0.25	16
R-1132a	CF2 = CH2	1, 1-difluoroethylene	A2	500	2.0	8.1
R-1150	CH2=CH2	Ethene (ethylene)	A3	200	––	2.2
R-1224yd(Z)	CF3CF=CHCl	(Z)-1-chloro-2,3,3,3-tetrafluoropropen	A1	1000	23	––
R-1233zd(E)	CF3CH=CHCl	Trans-1-chloro-3,3,3-trifluoro-1- propene	A1	800	5.3	––
R-1234yf	CF3CF=CH2	2, 3, 3, 3-tetrafluoro-1-propene	A2L	500	4.5	18.0
R-1234ze(E)	CF3CH=CFH	Trans-1,3,3,3- tetrafluoro-1-propene	A2L	800	4.7	18.8
R-1270	CH3CH=CH2	Propene (propylene)	A3	500	0.11	2.9
R-1336mzz(E)	CF3CH=CHCF3	Trans-1,1,1,4,4,4-hexafluoro-2-butene	A1	400	3.0	––
R-1336mzz(Z)	CF3CHCHCF3	Cis-1,1,1,4,4,4-hexaflouro-2-butene	A1	500	5.2	––

For SI units: 1 pound = 0.453 kg, 1 cubic foot = 0.0283 m [3]

Notes: 1 The preferred chemical name is followed by the popular name in parenthesis. 2 The OELs are 8-hour TWAs; a “C” designation denotes a ceiling limit. 3 Azeotropic refrigerants exhibit some segregation of components at conditions of temperature and pressure other than those at which they were formulated. The extent of segregation depends on the particular azeotrope and hardware system configuration. 4 The exact composition of this azeotrope is in question and additional experimental studies are needed. 5 R-507, R-508, and R-509 are allowed alternative designations for R-507A, R-508A, and R-509A due to a change in designations after assignment of R-500 through R-509. Corresponding changes were not made for R-500 through R-506. 6 The RCL values for these refrigerant blends are approximated in the absence of adequate data for a component comprising less than 4 percent m/m of the blend and expected to have a small influence in an acute, accidental release. 7 In accordance with Section 1102.3, ammonia refrigeration systems are not regulated by this chapter. R-717 (ammonia) is included in this table because the table is extracted from ASHRAE 34 and is not capable of being modified. 8 LFL is based on WCF @ 73.4°F (23°C) unless otherwise noted. 9 WCFF LFL @ 140°F (60°C). 10 WCFF LFL @ 73.4°F (23°C). 11 WCF LFL @ 212°F (100°C).

254 2025 CALIFORNIA MECHANICAL CODE

CALIFORNIA MECHANICAL CODE – MATRIX ADOPTION TABLE