UN/NA Number Reference
DOT Class 6.1 Toxic Substance placard

UN 2480: Methyl isocyanate

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2480 is assigned the proper shipping name Methyl isocyanate in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 6.1 Toxic Substance material, Packing Group I. Required label(s): 6.1, 3.

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 155)

Hazards: TOXIC. Corrosive. Flammable or water-reactive. Produces toxic gases on water contact.

Fire: DO NOT use water unless no alternative. Dry chemical, CO2.

Spill: Do not touch. Keep dry. Use water spray with caution.

Chemical and Physical Properties

Methyl isocyanate appears as a colorless low-boiling liquid (b.p. 39 °C) that is denser than water. Flash point is less than 20 °F. Very toxic by inhalation. Can be absorbed through the skin. Has a sharp odor, but the sense of smell cannot be relied upon to warn of the presence of vapors at low concentrations. Rate of onset: Immediate Persistence: Minutes to hours Odor threshold: 2.1 ppm Source/use/other hazard: Intermediate in manufacturing; reacts with H20 (don't use in fire).

CAS Number: 624-83-9
Molecular Formula: C2H3NO
Molecular Weight: 57.05 g/mol
Color / Form: Colorless liquid
Odor: Sharp, unpleasant odor
Boiling Point: 102 F
Melting Point: -112 °F (EPA, 1998)
Flash Point: 19 F
Autoignition: 995 °F (USCG, 1999)
Specific Gravity: 0.9599 (floats on water)
Vapor Pressure: 348 mmHg at 68 F
Vapor Density: About twice as heavy as air (EPA, 1998) (Relative to Air)
Water Solubility: Decomposes

Regulatory Data

CERCLA RQ (40 CFR 302.4)
10 lb
EPCRA TPQ (40 CFR 355)
500 lb
OSHA PEL
TWA 0.02 ppm (0.05 mg/m³) [skin]
NIOSH REL
TWA 0.02 ppm (0.05 mg/m³) [skin]
IDLH
0
RCRA Waste Code(s)
[object Object]

A release of this material at or above its CERCLA reportable quantity (10 lb) requires immediate notification to the National Response Center at 800-424-8802.

Special Provisions

49 CFR 172.102 special provision codes for this entry: 1, B9, B14, B30, T22, TP2, TP13, TP38, TP44. 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.

Need the full interactive record? Open UN 2480 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.