UN/NA Number Reference
DOT Class 2.2 Non-Flammable Gas placard

UN 1018: Chlorodifluoromethane

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1018 is assigned the proper shipping name Chlorodifluoromethane in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 2.2 Non-Flammable Gas material. Required label(s): 2.2.

Packing group indicates the degree of danger within a hazard class: PG I is high danger, PG II medium, PG III low. The proper shipping name, hazard class, UN number, and packing group together form the basic shipping description that must appear on shipping papers and, where required, on the package and placard.

Emergency Response (ERG Guide 126)

Hazards: May cause asphyxiation. May cause frostbite. Containers may rocket.

Fire: Let fire burn unless leak can be stopped. Cool surrounding containers with water.

Spill: Stop leak if safe. Ventilate area. Prevent gas from entering low areas.

Chemical and Physical Properties

Chlorodifluoromethane is a colorless gas with an ethereal odor. It is shipped as a liquefied gas under its own vapor pressure. It is noncombustible. It can asphyxiate by the displacement of air. Contact with the liquid can cause frostbite. Toxic gases can be produced in fires involving this material. Exposure of the container to prolonged heat or fire may cause it to rupture violently and rocket.

CAS Number: 75-45-6
Molecular Formula: CHClF2
Molecular Weight: 86.47 g/mol
Color / Form: Colorless gas ... [Note: Shipped as a liquefied compressed gas]
Odor: Nearly odorless
Boiling Point: -40.9 F
Melting Point: -231 °F (NIOSH, 2024)
Autoignition: Not flammable (USCG, 1999)
Specific Gravity: 1.41 at -40 F
Vapor Pressure: 10991.42 mmHg
Vapor Density: 3.11 (heavier than air)
Water Solubility: 0.3 % at 77 F
Log P: log Kow = 1.08

Regulatory Data

OSHA PEL
none
NIOSH REL
TWA 1000 ppm (3500 mg/m 3 ) ST 1250 ppm (4375 mg/m 3 )
IDLH
N

Special Provisions

49 CFR 172.102 special provision codes for this entry: T50. These codes modify the general requirements (packaging, quantity limits, exceptions) for this specific material. Look up each code in 49 CFR 172.102 for the full text.

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Reference data compiled from the DOT Hazardous Materials Table (49 CFR 172.101), the 2024 Emergency Response Guidebook, and public chemical databases (PubChem, NIOSH, EPA). Always verify the correct shipping description against the current regulation and the manufacturer's SDS Section 14 before shipping.