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Refrigerating machines, containing non-flammable, non-toxic gases, or ammonia solutions (UN2672)

HMT May 2026

UN / ID: UN 2857
Hazard class: 2.2
Packing group: —
ERG guide: ERG 126
Special provisions: SP A53
Source: 49 CFR §172 (2026/05)

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Refrigerating machines, containing non-flammable, non-toxic gases, or ammonia solutions (UN2672)

Emergency Response Guide No. 126

Hazardous Materials Table

Source: 49 CFR §172 (2026/05)

(3) Hazard Class

2.2
Non-toxic, non-flammable gases

(7) Special Provisions (§172.102)

×Note:
Special provisions may be very complex. The extracts are taken from 49 CFR §172.102. Please be careful with the information, as necessary, additional conditions may be applied that are not written here. Please check the original source and report bugs.

A53	Refrigerating machines and refrigerating machine components are not subject to the requirements of this subchapter when containing less than 12 kg (26.4 pounds) of a non-flammable gas or when containing 12 L (3 gallons) or less of ammonia solution (UN2672) (see §173.307). Browse special provision A53

(8) Packing Authorizations (§173.***)

(8A) Exceptions	306, 307	see 49 CFR §173.306, 307
(8B) Non-bulk	306	see 49 CFR §173.306
(8C) Bulk	306, 307	see 49 CFR §173.306, 307

(9) Quantity Limits

(9A) Passenger aircraft/rail	450 kg
(9B) Cargo aircraft only	450 kg

(10) Vessel stowage

(10A) Location	A Stowage category “A” means the material may be stowed “on deck” or “under deck” on a cargo vessel or on a passenger vessel. Source: 49 CFR §172.101(k)
(10B) Other	n/a

Segregation chart for load, transport, and storage

This chart shows whether loading, transport, or storage with other hazard classes is permitted, prohibited, or restricted. Based on 49 CFR §177.848.

Hazard class	8	7	6.1	5.2	5.1	4.3	4.2	4.1	3	2.3B	2.3A	2.2	2.1	1.6	1.5	1.4	1.3	1.1/1.2
1.1/1.2
1.3
1.4
1.5
1.6
2.1
2.2
2.3A
2.3B
3
4.1
4.2
4.3
5.1
5.2
6.1
7
8

	Must not be loaded, transported, or stored together in the same vehicle or facility.
	May be loaded, transported, or stored together.
	May be loaded, transported, or stored together only with restrictions.

Similar substances

UN / ID	Proper shipping name	Hazard class
UN 3138	Ethylene, acetylene and propylene in mixture, refrigerated liquid with at least 71.5 percent ethylene with not more than 22.5 percent acetylene and not more than 6 percent propylene	2.1
UN 1973	Chlorodifluoromethane and chloropentafluoroethane mixture or Refrigerant gas R 502 with fixed boiling point, with approximately 49 percent chlorodifluoromethane	2.2
UN 1972	Methane, refrigerated liquid (cryogenic liquid) or Natural gas, refrigerated liquid (cryogenic liquid, with high methane content)	2.1
UN 2599	Chlorotrifluoromethane and trifluoromethane azeotropic mixture or Refrigerant gas R 503 with approximately 60 percent chlorotrifluoromethane	2.2
UN 2602	Dichlorodifluoromethane and difluoroethane azeotropic mixture or Refrigerant gas R 500 with approximately 74 percent dichlorodifluoromethane	2.2
UN 3358	Refrigerating machines, containing flammable, non-toxic, liquefied gas	2.1
UN 3168	Gas sample, non-pressurized, toxic, flammable, n.o.s., not refrigerated liquid	2.3
UN 3167	Gas sample, non-pressurized, flammable, n.o.s., not refrigerated liquid	2.1
UN 3169	Gas sample, non-pressurized, toxic, n.o.s., not refrigerated liquid	2.3
UN 3312	Gas, refrigerated liquid, flammable, n.o.s. (cryogenic liquid)	2.1
UN 3311	Gas, refrigerated liquid, oxidizing, n.o.s. (cryogenic liquid)	2.2
UN 1958	1,2-Dichloro-1,1,2,2- tetrafluoroethane or Refrigerant gas R 114	2.2
UN 1003	Air, refrigerated liquid, (cryogenic liquid) non-pressurized	2.2
NA 9202	Carbon monoxide, refrigerated liquid (cryogenic liquid)	2.3
UN 3158	Gas, refrigerated liquid, n.o.s. (cryogenic liquid)	2.2

Refrigerating machines, containing non-flammable, non-toxic gases, or ammonia solutions (UN2672)

Refrigerating machines, containing non-flammable, non-toxic gases, or ammonia solutions (UN2672)

Hazardous Materials Table

(3) Hazard Class

(4) Identification number

(5) Packing Group

(6) Labels

(7) Special Provisions (§172.102)

(8) Packing Authorizations (§173.***)

(9) Quantity Limits

(10) Vessel stowage

Segregation chart for load, transport, and storage

Similar substances