UN/NA Number Reference
DOT Class 3 Flammable Liquid placard

UN 1243: Methyl formate

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1243 is assigned the proper shipping name Methyl formate in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 3 Flammable Liquid material, Packing Group I. Required label(s): 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 129)

Hazards: Flammable. Irritating vapor. May cause dizziness. Toxic if inhaled or absorbed through skin.

Fire: Alcohol-resistant foam, dry chemical, CO2, water spray.

Spill: Eliminate ignition sources. Ventilate area. Absorb with earth or sand.

Chemical and Physical Properties

Methyl formate appears as a clear colorless liquid with an agreeable odor. Flash point -27 °F. Less dense than water Vapors heavier than air.

CAS Number: 107-31-3
Molecular Formula: C2H4O2
Molecular Weight: 60.05 g/mol
Color / Form: Colorless liquid [Note: A gas above 89 degrees F].
Odor: Agreeable
Boiling Point: 88.7 F
Melting Point: -147.6 °F (NTP, 1992)
Flash Point: -26 F
Autoignition: 853 °F (USCG, 1999)
Specific Gravity: 0.977 (floats on water)
Vapor Pressure: 400 mmHg at 61 F
Vapor Density: 2.07 (heavier than air)
Water Solubility: greater than or equal to 100 mg/mL at 72 F
Log P: log Kow = 0.03

Regulatory Data

OSHA PEL
100 250 100 ppm (ST) 150 ppm
NIOSH REL
TWA 100 ppm (250 mg/m 3 ) ST 150 ppm (375 mg/m 3 )
IDLH
4500 ppm

Special Provisions

49 CFR 172.102 special provision codes for this entry: T11, TP2. 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 1243 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.