Methyl iodide

Synonyms

Iodomethane; Monoiodomethane; [NIOSH]

Category

Other Toxic Gases & Vapors

Description

Colorless liquid with a pungent, ether-like odor. [Note: Turns yellow, red, or brown on exposure to light & moisture.] [NIOSH]

Sources/Uses

Used as a methylating agent; used in microscopy because of its high refractive index; [ACGIH]

Comments

Liquid causes second degree burns after contact for a few minutes. [CHRIS] Corrosive to skin; [Quick CPC] In animal feeding studies, methyl iodide is hepatotoxic, "ten times as acutely toxic as carbon tetrachloride." After an industrial accident, an exposed chemical plant worker developed symptoms of central nervous system poisoning and died. [ACGIH] Inhalation can cause pulmonary edema, CNS depression, and death; [CAMEO] A lachrymator; [CHEMINFO] It is an acute pulmonary irritant that can cause chronic neurological symptoms after a heavy dermal exposure. [Reference #1]

Reference Link #1

Biomedical References

Yes

Yes

2 ppm

5 ppm

100 ppm

Excerpts from Documentation for IDLHs

Basis for original (SCP) IDLH: The chosen IDLH is based on the mouse 57­minute LC50 of 860 ppm [Buckell 1950 cited by Patty 1963]. . . . Other animal data: In a subchronic study, no rats died following exposures to 150 ppm for 6 hours/day for 3 days [Monsanto 1986]. \ Human data: None relevant for use in determining the revised IDLH.

405 mm Hg

LC50 (rat) = 1,300 mg/m3/4H

Explanatory Notes

VP from HSDB;

Reference Link #2

25 ppm

50 ppm

125 ppm

Yes

Yes

Other CNS neurotoxin

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

Skin burns

Not classifiable

Diseases

Occupational diseases associated with exposure to this agent:

• Encephalopathy, acute toxic
• Pneumonitis, toxic