UN/NA Number Reference
DOT Class 3 Flammable Liquid placard

UN 1231: Methyl acetate

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1231 is assigned the proper shipping name Methyl acetate in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 3 Flammable Liquid material, Packing Group II. 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 acetate appears as a clear colorless liquid with a fragrant odor. Moderately toxic. Flash point 14 °F. Vapors heavier than air.

CAS Number: 79-20-9
Molecular Formula: C3H6O2
Molecular Weight: 74.08 g/mol
Color / Form: Colorless, volatile liquid
Odor: Pleasant odor
Boiling Point: 134.4 F
Melting Point: -144 °F (NTP, 1992)
Flash Point: 14 F
Autoignition: 935 °F (USCG, 1999)
Specific Gravity: 0.927 (floats on water)
Vapor Pressure: 170 mmHg at 68 F
Vapor Density: 2.8 (heavier than air)
Water Solubility: greater than or equal to 100 mg/mL at 70 F
Log P: log Kow = 0.18

Regulatory Data

OSHA PEL
200 610 200 ppm (ST) 250 ppm
NIOSH REL
TWA 200 ppm (610 mg/m 3 ) ST 250 ppm (760 mg/m 3 )
IDLH
3100 ppm [10%LEL]

Special Provisions

49 CFR 172.102 special provision codes for this entry: IB2, T4, TP1. 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 1231 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.