Agent Name |
Methyl iodide |
Alternative Name |
Iodomethane |
CAS Number |
74-88-4 |
Formula |
C-H3-I |
Major Category |
Toxic Gases & Vapors |
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 |
Acute methyl iodide exposure with delayed neuropsy...[Am J Ind Med. 2005] - PubMed Result |
Exposure Assessment |
Skin Designation (ACGIH) |
Yes |
TIH |
Yes |
TLV (ACGIH) |
2 ppm |
PEL (OSHA) |
5 ppm |
IDLH (NIOSH) |
100 ppm |
Excerpts from Documentation for IDLHs |
Basis for original (SCP) IDLH: The chosen IDLH is based on the mouse 57�minute 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 |
Vapor Pressure |
400 mm Hg |
Lethal Concentration |
LC50 (rats) = 1,300 mg/m3/4H |
Adverse Effects |
Toxic Pneumonitis |
Yes |
Dermatotoxin |
Skin Burns |
Lacrimator |
Yes |
Neurotoxin |
Other CNS Neurotoxin |
Hepatotoxin |
Hepatotoxin, Secondary |
IARC Carcinogen |
Not Classifiable |
Links to Other NLM Databases |
Health Studies |
Human Health Effects from Hazardous Substances Data Bank: METHYL IODIDE
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