UN/NA Number Reference
DOT Class 8 Corrosive placard

UN 2215: Maleic anhydride

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2215 is assigned the proper shipping name Maleic anhydride in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 8 Corrosive material, Packing Group III. Required label(s): 8.

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 156)

Hazards: TOXIC or CORROSIVE. FLAMMABLE. Vapors may travel to ignition source.

Fire: Alcohol-resistant foam, dry chemical, CO2. Water spray for cooling only.

Spill: Eliminate ignition sources. Do not touch. Ventilate area.

Chemical and Physical Properties

Maleic anhydride appears as colorless crystalline needles, flakes, pellets, rods, briquettes, lumps or a fused mass. Melts at 113 °F. Shipped both as a solid and in the molten state. Vapors, fumes and dusts strong irritate the eyes, skin and mucous membranes. Flash point 218 °F. Autoignition temperature 890 °F. Used to make paints and plastics and other chemicals.

CAS Number: 108-31-6
Molecular Formula: C4H2O3
Molecular Weight: 98.06 g/mol
Color / Form: Orthorhombic needles from chloroform; commercial grades furnished in fused form, as briquettes
Odor: Pungent odor
Boiling Point: 387 to 390 F
Melting Point: 127 °F (NTP, 1992)
Flash Point: 218 F
Autoignition: 878 °F (USCG, 1999)
Specific Gravity: 1.43 (sinks in water)
Vapor Pressure: 0.2 mmHg
Vapor Density: 3.38 (heavier than air)
Water Solubility: Soluble
Log P: log Kow = 1.62
pH: pH of water solutions: 2.42 at 1X10-2 M; 2.62 at 5X10-3 M; 3.10 at 1X10-4 M

Regulatory Data

CERCLA RQ (40 CFR 302.4)
5000 lb
OSHA PEL
TWA 1 mg/m 3 (0.25 ppm)
NIOSH REL
TWA 1 mg/m 3 (0.25 ppm)
IDLH
10 mg/m 3
RCRA Waste Code(s)
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A release of this material at or above its CERCLA reportable quantity (5000 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: T4, TP3. 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 2215 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.