HazMat Tool — substance information

Dichlorofluoromethane or Refrigerant gas R21

HMT 15 June 2026
Reference only — HMT snapshot for inspection and audit support; not a shipping paper, placard mandate, or CVI record. Use Print / PDF below for field notes.
UN / ID
UN 1029
Hazard class
2.2
Packing group
ERG guide
ERG 126
Special provisions
SP T50
Source
49 CFR §172 (15 June 2026)

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Dichlorofluoromethane or Refrigerant gas R21


Dichlorofluoromethane or Freon 21 or R 21 is a halomethane or hydrochlorofluorocarbon with the formula CHCl2F. It is a colorless and odorless gas. It is produced by fluorination of chloroform using a catalyst such as antimony trifluoride: CHCl3 + HF → CHCl2F + HCl Wikipedia

Substance Data

Source: PubChem

CAS-Number

75-43-4

Flash Point

n/a

Boiling Point

n/a

Emergency Response Guide No. 126

Hazardous Materials Table

Source: 49 CFR §172 (15 June 2026)

(3) Hazard Class

2.2
Non-toxic, non-flammable gases

(4) Identification number Help

UN 1029

(5) Packing Group Help

n/a

(6) Labels Help

Non-toxic, non-flammable gases (2.2)

(7) Special Provisions (§172.102) Help

×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.
T50

(8) Packing Authorizations (§173.***) Help

(8A) Exceptions306see 49 CFR §173.306
(8B) Non-bulk304see 49 CFR §173.304
(8C) Bulk314, 315see 49 CFR §173.314, 315

(9) Quantity Limits Help

(9A) Passenger aircraft/rail75 kg
(9B) Cargo aircraft only150 kg

(10) Vessel stowage Help

(10A) Location
(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.

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