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

UN 2451: Nitrogen trifluoride

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2451 is assigned the proper shipping name Nitrogen trifluoride 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, 5.1.

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 122)

Hazards: Oxidizer. Vigorously accelerates combustion. May cause fire or explosion on contact with fuels.

Fire: Use water only. Do not use dry chemical or CO2. Cool containers with flooding water.

Spill: Stop leak if safe. Do not touch. Keep combustibles away.

Chemical and Physical Properties

Nitrogen trifluoride appears as a colorless gas with a moldy odor. Very toxic by inhalation. Slightly soluble in water. Corrosive to tissue. Under prolonged exposure to fire or heat the containers may rupture violently and rocket. Used to make other chemicals and as a component of rocket fuels.

CAS Number: 7783-54-2
Molecular Formula: F3N
Molecular Weight: 71.002 g/mol
Color / Form: Colorless gas [Note: Shipped as a nonliquified compressed gas]
Odor: Moldy odor
Boiling Point: -200 F
Melting Point: -340 °F (NIOSH, 2024)
Specific Gravity: 2.902 g/L
Vapor Pressure: greater than 1 atm
Vapor Density: 2.46 (heavier than air)
Water Solubility: Slight

Regulatory Data

OSHA PEL
TWA 10 ppm (29 mg/m 3 )
NIOSH REL
TWA 10 ppm (29 mg/m 3 )
IDLH
1000 ppm

Need the full interactive record? Open UN 2451 in the SpillNerd lookup tool for the live database entry with placard graphics, GHS pictograms, full segregation tables, and synonym search. For another material, use the UN number and chemical lookup.

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.