Methylhydrazine

Synonyms

Monomethylhydrazine; MMH; Methyl hydrazine; [NIOSH]

Category

Other Toxic Gases & Vapors

Description

Fuming, colorless liquid with an ammonia-like odor; [NIOSH]

Sources/Uses

Used as a rocket fuel, solvent, and chemical intermediate; [ACGIH]

Comments

Liquid causes second or third degree burns after short contact; [CHRIS] Toxic effects resemble those of hydrazine with mucous membrane irritation, methemoglobinemia, hemolytic anemia, and central nervous system injury; [ACGIH] May produce pulmonary edema after high inhalation exposure; [ICSC] In high-dose reproductive studies of animals, hydrazine derivatives (hydrazine, MMH, and UDMH) cause testicular damage and fetal loss, and hydrazine causes birth defects. [Frazier, p. 341-2] Hydrazines antagonize GABA in the CNS causing excitation and seizures. Pyridoxine, vitamin B6, is a specific antidote for this effect. [AHLS, p. 426]

Biomedical References

Yes

Yes

0.01 ppm

Ceiling(OSHA) = 0.2 ppm

20 ppm

Excerpts from Documentation for IDLHs

Basis for original (SCP) IDLH: The chosen IDLH is based on the report by Jacobson et al. [1955] of a mouse LC50 of 56 ppm. . . . Human data: None relevant for use in determining the revised IDLH.

50 mm Hg

1.7 ppm

LC50 (rat) = 34 ppm/4 hr

Explanatory Notes

1­hour SPEGL = 0.24 ppm; [NRC 1985] Odor threshold from CHEMINFO; VP from HSDB;

Reference Link #2

may ignite at ambient temp

Yes

MetHgb is secondary toxic effect

Other CNS neurotoxin

Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion

Yes

Skin burns

Confirmed Animal

Diseases

Occupational diseases associated with exposure to this agent:

• Encephalopathy, acute toxic
• Pneumonitis, toxic