HazMat Tool — substance information
Reference only — not a shipping paper, placard mandate, or CVI record.
Chlorodifluoromethane or Refrigerant gas R 22
HMT 15 June 2026- UN / ID
- UN 1018
- Hazard class
- 2.2
- Packing group
- —
- ERG guide
- ERG 126
- Special provisions
- SP T50
- Source
- 49 CFR §172 (15 June 2026)
Chlorodifluoromethane or Refrigerant gas R 22
Chlorodifluoromethane or difluoromonochloromethane is a hydrochlorofluorocarbon (HCFC). This colorless gas is better known as HCFC-22, or R-22, or CHClF2. It was commonly used as a propellant and refrigerant. These applications were phased out under the Montreal Protocol in developed countries in 2020 due to the compound's ozone depletion potential (ODP) and high global warming potential (GWP), and in developing countries this process will be completed by 2030 Wikipedia
Substance Data
Source: PubChem (HSDB, 04.12.2019)CAS-Number75-45-6 |
Flash Point— | Boiling Point— |
| Emergency Response Guide No. 126 |
Hazardous Materials Table
Source: 49 CFR §172 (15 June 2026)(3) Hazard class2.2Non-toxic, non-flammable gases |
(4) Identification number |
(5) Packing Group |
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(6) Labels |
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(7) Special Provisions (§172.102)
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| T50 |
|---|
(8) Packing Authorizations (§173.***) 
| (8A) Exceptions | 306 | see 49 CFR §173.306 |
|---|---|---|
| (8B) Non-bulk | 304 | see 49 CFR §173.304 |
| (8C) Bulk | 314, 315 | see 49 CFR §173.314, 315 |
(9) Quantity Limits 
| (9A) Passenger aircraft/rail | 75 kg |
|---|---|
| (9B) Cargo aircraft only | 150 kg |
(10) Vessel stowage 
| (10A) Location | |
|---|---|
| (10B) Other | — |
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. |