UN/NA Number Reference
DOT Class 8 Corrosive placard

UN 1831: Sulfuric acid, fuming

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1831 is assigned the proper shipping name Sulfuric acid, fuming in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 8 Corrosive material, Packing Group I. Required label(s): 8, 6.1.

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 137)

Hazards: Produce flammable gases on contact with water. May ignite on contact with water. Some react violently with water.

Fire: DO NOT use water or foam. Use dry chemical, dry sand, or soda ash.

Spill: Do not touch. Keep material dry. Move containers from water. Dike to prevent water contact.

Chemical and Physical Properties

Thick fuming yellow liquid. Density 16.5 lb / gal. Very toxic by inhalation. Corrosive to metals and tissue, quickly causing severe burns. Used to make chemicals, dyes, explosives and in petroleum refining.

CAS Number: 8014-95-7
Molecular Formula: H2O7S2
Molecular Weight: 178.15 g/mol
Color / Form: Colorless or slightly colored, viscous liquid
Autoignition: Not flammable (USCG, 1999)
Specific Gravity: 1.91 to 1.97
Vapor Pressure: approximately 20 kPa at 40 C /50% SO3, wt % (% Oleum)/
Vapor Density: Relative vapor density (air = 1): 3-3.3
Water Solubility: Solubility in water: miscible, reaction

Regulatory Data

CERCLA RQ (40 CFR 302.4)
1000 lb

A release of this material at or above its CERCLA reportable quantity (1000 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: 2, B9, B14, B32, B77, B84, N34, T20, TP2, TP12, TP13. 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 1831 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.