UN/NA Number Reference
DOT Class 8 Corrosive placard

UN 3463: Propionic acid

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 3463 is assigned the proper shipping name Propionic acid in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 8 Corrosive material, Packing Group II. Required label(s): 8, 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 132)

Hazards: HIGHLY FLAMMABLE. CORROSIVE. Causes burns. Vapors may form explosive mixture with air.

Fire: Alcohol-resistant foam, dry chemical, CO2. Do not use water jet. Cool containers.

Spill: Eliminate ignition sources. Do not touch. Stop leak if safe. Use foam.

Chemical and Physical Properties

Propionic acid is a colorless liquid with a sharp rancid odor. Produces irritating vapor. (USCG, 1999)

CAS Number: 79-09-4
Molecular Formula: C3H6O2
Molecular Weight: 74.08 g/mol
Color / Form: Colorless, oily liquid [Note: A solid below 5 degrees F]
Odor: Slightly pungent disagreeable, rancid odor
Boiling Point: 285.3 F
Melting Point: -6.7 °F (NTP, 1992)
Flash Point: 130 F
Autoignition: 870 °F (USCG, 1999)
Specific Gravity: 0.995 (floats on water)
Vapor Pressure: 2.9 mmHg at 68 F
Vapor Density: 2.56 (heavier than air)
Water Solubility: greater than or equal to 100 mg/mL at 72 F
Log P: 0.33

Regulatory Data

CERCLA RQ (40 CFR 302.4)
5000 lb
OSHA PEL
none
NIOSH REL
TWA 10 ppm (30 mg/m 3 ) ST 15 ppm (45 mg/m 3 )
IDLH
N

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: IB2, T7, 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 3463 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.