Methyl chloride

  • Chloromethane
  • Refrigerant gas R-40
  • Monochloromethane
Formula
CH3Cl
Structure
Description
A colorless gas with a faint sweet odor.
Uses
Refrigerant.

Registry Numbers and Inventories.
CAS
74-87-3
EC (EINECS/ELINCS)
200-817-4
EC Index Number
602-001-00-7
EC Class
Extremely flammable; Carcinogenic Category 3; Harmful
RTECS
PA6300000
RTECS class
Tumorigen; Mutagen; Reproductive Effector; Human Data
UN (DOT)
1063
Merck
12,6121
Beilstein/Gmelin
1696839
Beilstein Reference
4-01-00-00028
RCRA
U045
EPA OPP
53202
Swiss Giftliste 1
G-1921
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
CH3Cl
Formula mass
50.49
Melting point, °C
-97.2
Boiling point, °C
-24.2
Vapor pressure, mmHg
2315 (5 C)
Vapor density (air=1)
1.8
Odor Threshold Odor threshold 10 ppm
Critical temperature
143
Critical pressure
65.9
Density
0.9523 g/cm3 (0 C)
Solubility in water
5.2 g/L (25 C)
Viscosity
0.1834 cp (20 C)
Surface tension
16.2 g/s2 (20 C)
Refractive index
1.3389 (20 C)
Dipole moment
1.87 D
Dielectric constant
1.01 (20 C)
Partition coefficient, pKow
0.91
Heat of fusion
6.4 kJ/mol
Heat of vaporization
20.1 kJ/mol
Heat of combustion
-6551 kJ/mol

Hazards and Protection.
Storage
Cool below 40 C, well-ventilated area away from sources of ignition. No exposure to direct sunlight. Protect containers against physical damage. Electrical equipment of spark-resistant construction preferred. outside or detached storage preferred.
Handling
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection
Wear appropriate protective gloves, clothing and goggles. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.
Respirators
At any detectable concentration - Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode. Any supplied-air respirator with full facepiece and operated in a pressure-demand or other positive-pressure mode in combination with a separate escape supply. Escape - Any appropriate escape-type, self-contained breathing apparatus. For Unknown Concentrations or Immediately Dangerous to Life or Health - Any supplied-air respirator with full facepiece and operated in a pressure-demand or other positive-pressure mode in combination with a separate escape supply. Any self-contained breathing apparatus with a full facepiece.
Small spills/leaks
Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors.
Stability
Stable at normal temperatures and pressure.
Incompatibilities
Can react vigorously with oxidizing agents May react explosively with sodium, potassium, sodium-potassium alloy, magnesium, zinc Reacts with aluminum powder in the presence of catalytic amounts of aluminum chloride to form pyrophoric trimethylaluminum.
Decomposition
Phosgene, acid halides, oxides of carbon.

Fire.
Flash Point,°C
-66
Autoignition, °C
632
Upper exp. limit, %
17.4
Lower exp. limit, %
8.1
Fire fighting
Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible.
Fire potential
Very flammable, combustion imminent. In contact with al, product may ignite spontaneously in air. Do not use al, zn, mg, or alloys.
Hazards
Its vapors are heavier than air, and a flame can flash back to the source of leak very easily.
Combustion products
Toxic and irritating gases are generated in fires.
Health
2
 
Flammability
4
 
 
Reactivity
0
 

Health.
Exposure limit(s)
50 ppm
Poison_Class
3
Exposure effects
Exposure to low concentrations usually results in fatigue and drowsiness. Exposure to high concentrations may result in dizziness, drowsiness, headache, giddiness, incoordination, confusion, staggering gait, slurred speech, and weakness followed by delerium, paralysis, seizures, and coma. Birth defects have been produced in mice and rats. Methyl chloride was one of several substances implicated in sacral agenesis in humans, but its role as a human reproductive hazard is unproven.
   Ingestion
Exposure to lower concentrations usually results in mild gi upset. High concentrations may result in nausea, vomiting, diarrhea, and abdominal pain.
   Inhalation
Methyl chloride may produce nausea, vomiting, diarrhea, headache, drowsiness, symptoms of drunkenness, visual disturbances, bluish skin color, lung congestion, nerve damage, paralysis, convulsions and coma.
   Skin
Exposure may result in irritation, blisters, symptoms of drunkenness, nerve damage.
   Eyes
Diplopia, dimness of vision, and widely dilated pupils that are either sluggishly reactive or unreactive to light may be noted. Visual changes may persist after resolution of other symptoms.

First aid
 
   Ingestion
This compound is a gas, therefore inhalation is the first route of exposure.
   Inhalation
IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used.
   Skin
CAUTION: Exposure of skin to compressed gases may result in freezing of the skin. Treatment for frostbite may be necessary. Remove the victim from the source of contamination. IMMEDIATELY wash affected areas gently with COLD water (and soap, if necessary) while removing and isolating all contaminated clothing. Dry carefully with clean, soft towels. If symptoms such as inflammation or irritation develop, IMMEDIATELY call a physician or go to a hospital for treatment.
   Eyes
First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

Transport.
UN number
1063
Response guide
Hazard class
2.1
USCG CHRIS Code
MTC
 
36 Halogenated hydrocarbons
Std. Transport #
4905761
 
IMO Gas Code
B