UN/NA Number Reference
DOT Class 8 Corrosive placard

UN 2240: Chromosulfuric acid

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2240 is assigned the proper shipping name Chromosulfuric acid 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.

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 154)

Hazards: TOXIC. Corrosive. Non-combustible but may decompose producing toxic fumes when heated.

Fire: Use agent appropriate for surrounding fire. Cool containers.

Spill: Do not touch. Avoid inhalation. Use water spray to reduce fumes.

Chemical and Physical Properties

Chromic sulfate is a dark green to violet crystalline material. Used in paints and inks, ceramics, and in textile dyeing. It is noncombustible. The primary hazard of this material is the potential for environmental damage if released. Immediate steps should be taken to limit its spread to the environment.

CAS Number: 10101-53-8
Molecular Formula: Cr2O12S3
Molecular Weight: 392.2 g/mol
Color / Form: Peach-colored solid
Boiling Point: Loses water of hydration
Melting Point: 212 °F (USCG, 1999)
Specific Gravity: 3.012 (sinks in water)
Water Solubility: Practically insoluble in water
pH: Trivalent chromium compounds are amphoteric

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: A7, B4, B6, N34, T10, TP2, 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 2240 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.