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Chloromethane

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CH3Cl · 50.49 g/mol

Also called methyl chloride, R-40

Open in Athanor
The structure of Chloromethane
Drawn from its SMILES with RDKit420
FlammableCompressed gasHealth hazardDangerExtremely flammable gas · Suspected of causing cancer

Names and identifiers

IUPAC name
chloromethane
Synonyms
methyl chloride, R-40, METHYL CHLORIDE
+ 36 more

Monochloromethane, Methane, chloro-, Methylchloride, Artic, CH3Cl, Methylchlorid, Clorometano, Chloor-methaan, Metylu chlorek, Chlor-methan, Cloruro di metile, Chlorure de methyle, RCRA waste number U045, DTXSID0021541, A6R43525YO, CHEBI:36014, Chloride, Methyl, RefChem:157816, Chloromethane; methyl chloride, DTXCID701541, 200-817-4, R 40, MeCl, Refrigerant R40, MFCD00000872, Methyl Chloride (ca. 5.7% in Tetrahydrofuran, ca. 1mol/L), Freon 40, Caswell No. 557, Clorometano [Italian], Chlor-methan [German], Chlorocarbon, Methylchlorid [German], Chloor-methaan [Dutch], Metylu chlorek [Polish], Cloruro di metile [Italian], Chlorure de methyle [French]

Molecular formula
CH3Cl
Empirical formula
CH3Cl
Molecular weight
50.49 g/mol
Exact mass
49.99233
CAS number
74-87-3
PubChem CID
6327
Canonical SMILES
CCl
Isomeric SMILES
CCl
InChI
InChI=1S/CH3Cl/c1-2/h1H3
InChIKey
NEHMKBQYUWJMIP-UHFFFAOYSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Physical properties

TemperaturePressureDensity
Appearance
Colorless compressed gas or liquid[6]
6 values

From Hazardous Substances Data Bank (HSDB), the most authoritative source here.

ValueAs writtenSource
–Methyl chloride appears as a colorless gas with a faint sweet odor. Shipped as a liquid under its vapor pressure. A leak may either be liquid or vapor. Contact with the liquid may cause frostbite by evaporative cooling. Easily ignited. Vapors heavier than air. Can asphyxiate by the displacement of air. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket. Used to make other chemicals and as a herbicide.[1] CAMEO Chemicals
–Gas Vapor; CBI; Liquid[2] EPA Chemical Data Reporting (CDR)
–COLOURLESS LIQUEFIED GAS.[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–Colorless gas with a faint, sweet odor which is not noticeable at dangerous concentrations.[4] Occupational Safety and Health Administration (OSHA)
–Colorless gas with a faint, sweet odor which is not noticeable at dangerous concentrations. [Note: Shipped as a liquefied compressed gas.][5] The National Institute for Occupational Safety and Health (NIOSH)
–shownColorless compressed gas or liquid[6] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 823
Odor
Faint sweet ethereal odor[6]
Melting point
-97.7 °C[7]
5 values

5 of 5 sources agree on it (most common value).

ValueAs writtenSource
−97 °C-143 °F (NTP, 1992)[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
−97 °C-97 °C[3] ILO-WHO International Chemical Safety Cards (ICSCs)
−98 °C-144 °F[4] Occupational Safety and Health Administration (OSHA)
−97.7 °Cshown-97.7 °C[7] PAC Chemical Database, U.S. Department of Energy
−98 °C-144 °F[5] The National Institute for Occupational Safety and Health (NIOSH)
Boiling point
-24.09 °C @760 [mmHg][7]
5 values

5 of 5 sources agree on it (most common value).

ValueAs writtenSource
−24.2 °C-11.6 °F at 760 mmHg (NTP, 1992)[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
−23.7 °C-23.7 °C[3] ILO-WHO International Chemical Safety Cards (ICSCs)
−24 °C-12 °F[4] Occupational Safety and Health Administration (OSHA)
−24.1 °Cshown-24.09 °C @760 [mm Hg][7] PAC Chemical Database, U.S. Department of Energy
−24 °C-12 °F[5] The National Institute for Occupational Safety and Health (NIOSH)
Density
0.911 @25 °C[7]
5 values

2 of 5 sources agree on it (most common value).

ValueAs writtenSource
–0.997 at -11.2 °F (USCG, 1999) - Less dense than water[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
–Relative density (water = 1): 0.91[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–0.997 at -11.2 °F[4] Occupational Safety and Health Administration (OSHA)
–shown0.911 @25 °C[7] PAC Chemical Database, U.S. Department of Energy
–1.78(relative gas density)[5] The National Institute for Occupational Safety and Health (NIOSH)

7 more values were reported but failed the checks (unreadable or out of range), so they are not shown.

Solubility in water
Solubility in water, g/100ml at 25 °C: 0.5[3]
5 values

From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.

ValueAs writtenSource
–Slightly soluble (NTP, 1992)[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
–In water, 5040 mg/L at 25 °C[6] Hazardous Substances Data Bank (HSDB)cites Horvath AL; Halogenated hydrocarbons: solubility-miscibility with water. New York, NY: Marcel Dekker, Inc pp. 889 (1982)
–Solubility at 20 °C (mL/100 mL): benzene 4723, carbon tetrachloride 3756, glacial acetic acid 3679, ethanol 3740; miscible with chloroform, ether[6] Hazardous Substances Data Bank (HSDB)
–shownSolubility in water, g/100ml at 25 °C: 0.5[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–0.5%[5] The National Institute for Occupational Safety and Health (NIOSH)
log P
0.91[3]
2 values

2 of 2 sources agree on it (most common value).

ValueAs writtenSource
–log Kow = 0.91[6] Hazardous Substances Data Bank (HSDB)cites Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 3
–shown0.91[3] ILO-WHO International Chemical Safety Cards (ICSCs)
Vapor pressure
4300 mmHg at 25 °C[6]
5 values

2 of 4 sources agree on it (most common value).

ValueAs writtenSource
760 mmHg760 mmHg at -11 °F[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
3672 mmHg3672 mmHg at 68 °F (NTP, 1992)[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
4300 mmHgshown4300 mm Hg at 25 °C[6] Hazardous Substances Data Bank (HSDB)cites Daubert, T.E., R.P. Danner. Physical and Thermodynamic Properties of Pure Chemicals Data Compilation. Washington, D.C.: Taylor and Francis, 1989.
4300 mmHgVapor pressure, kPa at 25 °C: 573[3] ILO-WHO International Chemical Safety Cards (ICSCs)
750 mmHg750 [mm Hg] @-24.4 °C[7] PAC Chemical Database, U.S. Department of Energy

2 more values were reported but failed the checks (unreadable or out of range), so they are not shown.

Flash point
-45.5 °C (-49.9 °F, NTP 1992)[1]
4 values

3 of 3 sources agree on it (most common value).

ValueAs writtenSource
−45.5 °Cshown-49.9 °F (NTP, 1992)[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
−46 °C-50 °F (closed cup)[6] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-83
< 0 °C<32 °F[6] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2408
−45.0 °C-49.0 °F[4] Occupational Safety and Health Administration (OSHA)
Autoignition temperature
632 °C (1170 °F)[6]
3 values

3 of 3 sources agree on it (most common value).

ValueAs writtenSource
632 °C1170 °F (USCG, 1999)[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
632 °Cshown1170 °F[6] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr. (ed) Sax's Dangerous Properties of Industrial Materials. 11th Edition. Wiley-Interscience, Wiley & Sons, Inc. Hoboken, NJ. 2004., p. 2408
632 °C632 °C[3] ILO-WHO International Chemical Safety Cards (ICSCs)
Viscosity
0.1834 cP at 20 °C[3]
2 values

Sources disagree; from ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative.

ValueAs writtenSource
–0.00027 Pa.s at 20 °C (liquid, 0.5 MPa)[6] Hazardous Substances Data Bank (HSDB)cites Rossberg M et al; Chloromethanes. Ullmann's Encyclopedia of Industrial Chemistry. 7th ed. (1999-2015). New York, NY: John Wiley & Sons. Online Posting Date: Oct 15, 2011.
–shown0.1834 cP at 20 °C[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.

Calculated

Heavy atoms
2
Rings
0
Aromatic rings
0
Fraction sp³ carbons (Fsp3)
1
H-bond donors
0
H-bond acceptors
0
Rotatable bonds
0
TPSA (Ų)
0
Formal charge
0
XLogP3
0.8 PubChem
Complexity
2 PubChem
Stereocenters
None
Double-bond geometry
None specified
Point group
C3v of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

  • C23.79%
  • H5.99%
  • Cl70.22%

Isotope pattern

100%49.9921.1%50.99632%51.98952.993

Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.

Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.

Predicted

log P
0.85 Crippen (Wildman and Crippen 1999)
log S (water solubility)
-0.69 ESOL (Delaney 2004), log mol/L
Synthetic accessibility
3.05 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

  • Molecular weight ≤ 500: 50.49
  • log P ≤ 5 (Crippen): 0.85
  • H-bond donors ≤ 5: 0
  • H-bond acceptors ≤ 10: 0

Passes all four rules.

¹³C NMR shifts, predicted

Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.

Safety

Danger

Harmonized EU classification (CLP Annex VI). Source [8].

  • Flammable
  • Compressed gas
  • Health hazard
420
NFPA 704[6]
  • H220Extremely flammable gas
  • H351Suspected of causing cancer

Precautionary statements: P203, P210, P222, P260, P280, P318, P319, P377, P381, P403, P405, P501

View all classifications (3)
  • [8] Regulation (EC) No 1272/2008 of the European Parliament and of the Council · DangerH220, H351
  • [9] European Chemicals Agency (ECHA) · 1,298 reports · DangerH220, H280, H351, H361, H361f
  • [6] Hazardous Substances Data Bank (HSDB) · DangerH220, H280, H351, H361, H373

Exposure limits

  • PEL-TWA (8-Hour Time Weighted Average): 100 ppm (210 mg/m³)[4]
  • PEL-C (Ceiling): 200 ppm; 300 ppm (Peak - 5 min in any 3 hrs)[4]
  • PEL: TWA 100 ppm C 200 ppm 300 ppm (5-minute maximum peak in any 3 hours) See Appendix G[5]
  • REL: Ca See Appendix A[5]
  • TLV: 50 ppm as TWA; 100 ppm as STEL; (skin); A4 (not classifiable as a human carcinogen).[3]
  • TLV-TWA (Time Weighted Average): 50 ppm [1992][4]

First aid

  • 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. Skin: Caution: Exposure of skin to compressed gases may result in freezing of the skin. Treatment for frostbite may be necessary.[1]
  • General First Aid: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped…[10]
  • General First Aid: · Call 911 or emergency medical service. · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination. · Move victim to fresh air if it can be done safely. · Administer oxygen if breathing is difficult. · If victim is not breathing: -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance. -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped…[10]
  • (General first aid procedures) Eye: Frostbite - If eye tissue is frozen, seek medical attention immediately; if tissue is not frozen, immediately and thoroughly flush the eyes with large amounts of water for at least 15 minutes, occasionally lifting the lower and upper eyelids. If irritation, pain, swelling, lacrimation, or photophobia persist, get medical attention as soon as possible. Skin: Frostbite - Compressed gases may create low temperatures when they expand rapidly. Leaks and uses that allow rapid expansion may cause a frostbite hazard.[5]

Storage

  • Fireproof. Ventilation along the floor.[3]
  • Keep container tightly closed in a dry and well-ventilated place. Contents under pressure. Moisture sensitive. Storage class (TRGS 510): Gases[6]
  • Store in well-ventilated place controlled below 40 °C. No exposure to direct sunlight. ... Electrical equipment of spark-resistant construction is preferred.[6]
  • Store separately from all other flammable materials. ... Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Methyl chloride must be stored to avoid contact with oxidizers (such as perchlorates, peroxides, chlorates, nitrates, and permanganates) or chemically active metals (such as sodium, potassium, powdered aluminum, zinc, and magnesium), since violent reactions occur. Store in tightly closed containers in a cool, well-ventilated area away from heat and direct sunlight. Sources of ignition, such as smoking and[6]

Incompatibilities

  • Incompatible materials: Strong oxidizing agents, Iron[6]
  • Contact with chemically active metals such as potassium, powdered aluminum, magnesium and zinc will cause fires and explosions.[6]
  • Explodes on contact with interhalogens (e.g., bromine, trifluoride, bromine pentafluoride), magnesium and alloys, potassium and alloys, sodium and alloys, zinc. Potentially explosive reaction with aluminum when heated to 152 deg in a sealed container. Mixtures with aluminum chloride + ethylene react exothermically and then explode when pressurized to above 30 bar.[6]
  • Violent reaction with chemically active metals, such as potassium, powdered aluminum, zinc, and magnesium. Reaction with aluminum trichloride, ethylene. Reacts with water (hydrolizes) to form hydrochloric acid. Attacks many metals in the presence of moisture.[6]

Safety data sheets on the supplier’s page: Sigma-Aldrich, Veeprho, Molport.

Always read the supplier’s safety data sheet before working with it.

Spectra

Experimental spectra held by these sources; each link opens the source's own record.

Literature

Reading PubChem, OpenAlex and GSRS…

Bioactivity

Reading ChEMBL…

References

  1. [1]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
  2. [2]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
  3. [3]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
  4. [4]Occupational Safety and Health Administration (OSHA) · Public domain (US DOL) · via PubChem · retrieved 2026-10-14
  5. [5]The National Institute for Occupational Safety and Health (NIOSH) · Public domain (US CDC) · via PubChem · retrieved 2026-10-14
  6. [6]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
  7. [7]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
  8. [8]Regulation (EC) No 1272/2008 of the European Parliament and of the Council · EU reuse policy, CC BY 4.0 · via PubChem · retrieved 2026-10-14
  9. [9]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
  10. [10]Emergency Response Guidebook (ERG) · Public domain (US DOT) · via PubChem · retrieved 2026-10-14
  11. [11]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
  12. [12]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
  13. [13]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
  14. [14]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
  15. [15]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
  16. ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
  17. ·Literature on PubChem

Data last updated 2026-10-14.