UN/NA Number Reference
DOT Class 6.1 Toxic Substance placard

UN 1244: Methylhydrazine

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1244 is assigned the proper shipping name Methylhydrazine 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 I. Required label(s): 6.1, 3, 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 131)

Hazards: HIGHLY FLAMMABLE. TOXIC. May be fatal if inhaled, swallowed, or absorbed through skin. Vapors heavier than air.

Fire: Small: dry chemical, CO2, water spray, alcohol-resistant foam. Large: water spray, fog, alcohol-resistant foam.

Spill: Eliminate ignition sources. Do not touch. Stop leak if safe. Use vapor-suppressing foam. Ventilate area.

Chemical and Physical Properties

Methylhydrazine appears as a colorless liquid with an ammonia-like odor. Flash point below 75 °F. Spontaneous ignition may occur in contact with oxidizing materials. Very toxic by inhalation and by skin absorption. Produces toxic oxides of nitrogen during combustion. Rate of onset: Immediate Persistence: Hours - days Odor threshold: 1-10 ppm Source/use/other hazard: Solvent, rocket fuel; flammable; irritating to skin/eyes.

CAS Number: 60-34-4
Molecular Formula: CH6N2
Molecular Weight: 46.072 g/mol
Color / Form: Clear liquid
Odor: Odor characteristic of short chain, organic amines
Boiling Point: 190 F
Melting Point: -62.3 °F (EPA, 1998)
Flash Point: 158 F
Autoignition: 382 °F (USCG, 1999)
Specific Gravity: 0.874 (floats on water)
Vapor Pressure: 49.6 mmHg at 77 F
Vapor Density: 1.6 (heavier than air)
Water Solubility: Insoluble (<1 mg/ml at 75 F)
Log P: log Kow= -1.05
pH: Mildly alkaline base

Regulatory Data

CERCLA RQ (40 CFR 302.4)
10 lb
EPCRA TPQ (40 CFR 355)
500 lb
OSHA PEL
C 0.2 ppm (0.35 mg/m 3 ) [skin]
NIOSH REL
Ca C 0.04 ppm (0.08 mg/m 3 ) [2-hr]
IDLH
Ca [20 ppm]
RCRA Waste Code(s)
[object Object], [object Object]

A release of this material at or above its CERCLA reportable quantity (10 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: 1, B7, B9, B14, B30, B77, N34, T22, TP2, TP13, TP38, TP44. 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 1244 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.