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Methyl chloride

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Synonyms & Trade Names
Chloromethane, Monochloromethane
CAS No.
74-87-3
RTECS No.
PA6300000
DOT ID & Guide
1063 115
Formula
CH₃Cl
Conversion
1 ppm = 2.07 mg/m3
IDLH
Ca [2000 ppm]
See: 74873
Exposure Limits
NIOSH REL
Ca See Appendix A
OSHA PEL
TWA 100 ppm C 200 ppm 300 ppm (5-minute maximum peak in any 3 hours) See Appendix G
Measurement Methods
NIOSH 1001
See: NMAM or OSHA Methods
Physical Description
Colorless gas with a faint, sweet odor which is not noticeable at dangerous concentrations. [Note: Shipped as a liquefied compressed gas.]
Molecular Weight
50.5
Boiling Point
-12°F
Freezing Point
-144°F
Solubility
0.5%
Vapor Pressure
5.0 atm
Ionization Potential
11.28 eV
Flash Point
NA (Gas)
Upper Explosive Limit
17.4%
Lower Explosive Limit
8.1%
Relative Gas Density
1.78
Flammable Gas
Incompatibilities & Reactivities
Chemically-active metals such as potassium, powdered aluminum, zinc & magnesium; water [Note: Reacts with water (hydrolyzes) to form hydrochloric acid.]
Exposure Routes
inhalation, skin and/or eye contact (liquid)
Symptoms
dizziness, nausea, vomiting; visual disturbance, stagger, slurred speech, convulsions, coma; liver, kidney damage; liquid: frostbite; reproductive, teratogenic effects; [potential occupational carcinogen]
Target Organs
central nervous system, liver, kidneys, reproductive system
Cancer Site
[in animals: lung, kidney & forestomach tumors]
Personal Protection/Sanitation
(See protection codes)
Skin:Frostbite
Eyes:Frostbite
Wash skin:No recommendation
Remove:When wet (flammable)
Change:No recommendation
Provide:Frostbite wash
First Aid
(See procedures)
Eye:Frostbite
Skin:Frostbite
Breathing:Respiratory support
Respirator Recommendations

NIOSH

At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration:
(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode
(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

Escape:
Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

See also
INTRODUCTION   ICSC CARD: 0419   MEDICAL TESTS: 0140
Page last reviewed: October 30, 2019
Content source: National Institute for Occupational Safety and Health