UN/NA Number Reference
DOT Class 8 Corrosive placard

UN 2032: Nitric acid, fuming

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2032 is assigned the proper shipping name Nitric 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, 5.1, 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 157)

Hazards: TOXIC and/or CORROSIVE. Reacts with water. Non-combustible in themselves.

Fire: DO NOT use water. Dry chemical, CO2, dry sand.

Spill: Do not touch. Keep material dry.

Chemical and Physical Properties

Nitric acid, other than red fuming appears as a pale yellow to reddish brown liquid with reddish brown vapors and a suffocating odor. Very toxic by inhalation. Corrosive to metals or tissue. Accelerates the burning of combustible material and may cause ignition of combustible materials upon contact. Prolonged exposure to low concentrations or short term exposure to high concentrations may result in adverse health effects. Density 12 lb / gal.

CAS Number: 7697-37-2
Molecular Formula: HNO3
Molecular Weight: 63.013 g/mol
Color / Form: Transparent, colorless, or yellowish, fuming, hygroscopic, corrosive liquid
Odor: Characteristic choking odor
Boiling Point: 181 F
Melting Point: -44 °F (NIOSH, 2024)
Specific Gravity: 1.5 (sinks in water)
Vapor Pressure: 48 mmHg
Vapor Density: 2.2 (heavier than air)
Water Solubility: Miscible
Log P: -0.21

Regulatory Data

CERCLA RQ (40 CFR 302.4)
1000 lb
EPCRA TPQ (40 CFR 355)
1000 lb
OSHA PEL
TWA 2 ppm (5 mg/m 3 )
NIOSH REL
TWA 2 ppm (5 mg/m 3 ) ST 4 ppm (10 mg/m 3 )
IDLH
25 ppm

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, B32, T20, TP2, TP13, TP38, TP45. 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 2032 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.