Agent Name

Methyl chloride

Alternative Name

Chloromethane

CAS Number

74-87-3

Formula

C-H3-Cl

Major Category

Solvents

Synonyms

Chloromethane; Monochloromethane; [NIOSH] UN1063

Category

Chlorinated Aliphatics

Description

Colorless gas with a faint, sweet odor which is not noticeable at dangerous concentrations; Note: Shipped as a liquefied compressed gas; [NIOSH]

Sources/Uses

Methyl chloride is used as a methylating agent in the synthesis of many organic chemicals. [ACGIH]

Comments

Slurred speech and staggering gait were observed in six workers exposed at 200-400 ppm for at least 2 weeks, but no changes in blood chemistries were found in these six cases. Liver injury has been documented in animal studies. [ACGIH] Possible frostbite from contact with liquid; [NIOSH] In high-dose reproductive studies of mice and rats, methyl chloride causes testicular damage; it causes increased heart valve birth defects in mice only. [Frazier, p. 286-7] Compared to other haloalkanes, methyl chloride is nontoxic to the liver. Steatosis may be observed in high-dose feeding studies of animals. [Zimmerman, p. 333] Has acute effects on the CNS, heart, liver, and kidneys; Possible CNS and reproductive effects after chronic exposure; [ICSC]

Exposure Assessment
Skin Designation (ACGIH)

Yes

TLV (ACGIH)

50 ppm

STEL (ACGIH)

100 ppm

PEL (OSHA)

100 ppm, Ceiling(OSHA) = 200 ppm(300 ppm for 5-min peak in any 3 hrs)

MAK

50 ppm

IDLH (NIOSH)

2000 ppm

Odor Threshold Low

10 ppm

Lethal Concentration

LC50 (rat) = 5,300 mg/m3/4H

Explanatory Notes

Odor threshold from AIHA is >10 ppm; Flash point = -45.6 deg C;

Reference Link

ATSDR - ToxFAQs - Chloromethane

Flammability (NFPA)

4: Burns readily

Adverse Effects
Neurotoxin

CNS Solvent Syndrome

Hepatotoxin

Hepatotoxin, Secondary

Nephrotoxin

Yes

Reproductive Toxin

Yes

IARC Carcinogen

Not Classifiable

ACGIH Carcinogen

Not Classifiable

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

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Chemical Information

Search ChemIDplus

Biomedical References

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Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent: