UN/NA Number Reference
DOT Class 6.1 Toxic Substance placard

UN 3293: Hydrazine, aqueous solution

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 3293 is assigned the proper shipping name Hydrazine, aqueous solution in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 6.1 Toxic Substance material, Packing Group III. Required label(s): 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 153)

Hazards: TOXIC. Combustible. Corrosive. Causes burns. Toxic fumes when heated.

Fire: Small: dry chemical, CO2, water spray. Large: water spray, foam.

Spill: Do not touch. Stop leak if safe. Use water spray to reduce vapor.

Chemical and Physical Properties

Hydrazine, anhydrous appears as a colorless, fuming oily liquid with an ammonia-like odor. Flash point 99 °F. Explodes during distillation if traces of air are present. Toxic by inhalation and by skin absorption. Corrosive to tissue. Produces toxic oxides of nitrogen during combustion. Used as a rocket propellant and in fuel cells.

CAS Number: 302-01-2
Molecular Formula: H4N2
Molecular Weight: 32.046 g/mol
Color / Form: Colorless oily liquid
Odor: Penetrating odor resembling ammonia.
Boiling Point: 236.3 °F at 760 mmHg (EPA, 1998)
Melting Point: 36 °F (EPA, 1998)
Flash Point: 125.6 °F (EPA, 1998)
Autoignition: 518 °F (USCG, 1999)
Specific Gravity: 1.011 at 59 °F (EPA, 1998) - Denser than water; will sink
Vapor Pressure: 14.4 mmHg at 77 °F (EPA, 1998)
Vapor Density: Relative vapor density (air = 1): 1.1
Water Solubility: Miscible (NIOSH, 2024)
Log P: log Kow = -2.07
pH: Aqueous solutions of hydrazine are highly alkaline. pH of a 64 wt% aqueous solution of hydrazine is 12.75.

Regulatory Data

CERCLA RQ (40 CFR 302.4)
1 lb
EPCRA TPQ (40 CFR 355)
1000 lb
OSHA PEL
TWA 1 ppm (1.3 mg/m 3 ) [skin]
NIOSH REL
Ca C 0.03 ppm (0.04 mg/m 3 ) [2-hour]
IDLH
Ca [50 ppm]
RCRA Waste Code(s)
[object Object]

A release of this material at or above its CERCLA reportable quantity (1 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: IB3, T4, TP1. 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 3293 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.