UN/NA Number Reference

UN 1832: Sulfuric acid, spent

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1832 is assigned the proper shipping name Sulfuric acid, spent 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.

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

Sulfuric acid is a colorless oily liquid. It is soluble in water with release of heat. It is corrosive to metals and tissue. It will char wood and most other organic matter on contact, but is unlikely to cause a fire. Density 15 lb / gal. Long term exposure to low concentrations or short term exposure to high concentrations can result in adverse health effects from inhalation. It is used to make fertilizers and other chemicals, in petroleum refining, in iron and steel production, and for many other uses. Rate of onset: Immediate Persistence: Hours, days Odor threshold: Source/use/other hazard: Battery/dyes/paper/glue/metals industries; volcanic gas; toxic fumes when heated.

CAS Number: 7664-93-9

Molecular Formula: H2O4S

Molecular Weight: 98.08 g/mol

Color / Form: Colorless, oily liquid

Odor: Odorless

Boiling Point: 554 F

Melting Point: 50.65 °F (EPA, 1998)

Autoignition: Not flammable (USCG, 1999)

Specific Gravity: 1.841 (sinks in water)

Vapor Pressure: 1 mmHg at 294.8 F

Vapor Density: 3.4 (heavier than air)

Water Solubility: Miscible

pH: 1 N solution = 0.3; 0.1 N solution = 1.2; 0.01 N solution = 2.1

Regulatory Data

CERCLA RQ (40 CFR 302.4)

1000 lb

EPCRA TPQ (40 CFR 355)

1000 lb

OSHA PEL

1 0.1 mg/m 3 (ST) 3 mg/m 3

NIOSH REL

TWA 1 mg/m 3

IDLH

15 mg/m 3

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: A3, A7, B2, B83, B84, IB2, N34, T8, 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 1832 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.