Chloromethane , also known as methyl chloride , refrigerant-40 , R-40 or HCC 40 , is an organic compound with the chemical formula CH3Cl . One of the haloalkanes , it is a colourless, odorless, flammable gas. Methyl chloride is an important reagent in industrial chemistry, although it is rarely present in consumer products.


Chloromethane is an abundant organohalogen, human or natural, in the environment. 


Laboratory cultures of marine phytoplankton ( Phaeodactylum tricornutum , Phaeocystis sp., Thalassiosira weissflogii , Chaetoceros calcitrans , Isochrysis sp., Porphyridium sp., Synechococcus sp., Tetraselmis sp., Tetraselmis sp., Proleyii sp., hux produce hux , Emrocentrum sp., and Ch. But in relatively negligible quantities. A comprehensive study of 30 species of polar macroalgae showed that only Gigartina scottsbergii and Gymnogongarus antarcticus Significant amounts of CH3Cl have been released in


The salt marsh plant Batis maritima contains the enzyme methyl chloride transferase that catalyzes the synthesis of CH 3S adenosine-L-methionine and chlorine from chloride. [10] This protein has been purified and expressed in E. coli , and appears to be present in other organisms such as the white rot fungus ( Pellinus pomaceus ), red algae ( Endocladia muricata ), and the snow plant ( Mesembryanthemum Crystallinum ). it happens. of which is a known CH3Cl producer . [10] [11]

Sugarcane and Methyl Chloride Excretion

In the sugarcane industry, organic waste is usually burned in the power cogeneration process. When contaminated with chloride, this waste burns, releasing methyl chloride into the atmosphere. [12]

Interstellar detection

Chloromethane has been detected in a low-mass Class 0 protostellar binary, IRAS 16293 – 2422, using the Atacama Large Millimeter Array (ALMA). It was also detected in Comet 67P/Churyumov-Gerasimenko (67P/CG) using the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument on the Rosetta spacecraft. [13] The discovery suggests that chloromethane may have formed in star-forming regions before planets or life formed.


Chloromethane was first synthesized by French chemists Jean-Baptiste Dumas and Eugne Péligot in 1835 by boiling a mixture of methanol, sulfuric acid, and sodium chloride. This method is similar to what is used today.

Chloromethane is produced commercially by treating methanol with hydrochloric acid or hydrogen chloride, according to the chemical equation: [5]CH 3 OH + HCl → CH 3 Cl + H 2 O

A small amount of chloromethane is produced by treating a mixture of methane with chlorine at elevated temperatures. However, this method produces more chlorinated compounds such as dichloromethane, chloroform, and carbon tetrachloride. For this reason, methane chlorination is usually performed only when these other products are also desired. This chlorination method also generates hydrogen chloride, which poses disposal problems. [5]

spread in the environment

Most of the methyl chloride present in the atmosphere is eventually released into the atmosphere. After being released into the air, the atmospheric lifetime of this substance is approximately 10 months with many natural sinks, such as transport across the ocean, stratosphere, soil, etc. 

On the other hand, when the excreted methyl chloride is released into the water, it will be rapidly lost by evaporation. The [half-life] of this substance in terms of evaporation in the river, lagoon and lake is 2.1 hours, 25 hours and 18 days, respectively. The amount of methyl chloride in the stratosphere is estimated to be 2 x 10 6 tonnes per year, which is 20–25% of the total amount of chlorine emitted into the stratosphere annually.


Chloromethane is used extensively for the production of dimethyldichlorosilane and related organosilicon compounds. [5] These compounds are produced by direct process. The relevant reactions are (Me = CH 3 ):x MeCl + Si → Me 3 SiCl, Me 2 SiCl 2 , MeSiCl 3 , Me 4 Si 2 Cl 2 , …

Dimethyldichlorosilane (Me 2 SiCl 2 ) is of particular value (the precursor to silicon, but trimethylsilyl chloride (Me 3 SiCl) and methyltrichlorosilane (MeSiCl 3 ) are also valuable. Small amounts are used in the manufacture of butyl rubber and as a solvent in petroleum. Goes Refinement.

Chloromethane is employed as a methylating and chlorinating agent, for example in the production of methylcellulose. It is also used in many other fields: as an extractant for greases, oils and resins, as a propellant and blowing agent in polystyrene foam production, as a local anesthetic, an intermediate in pharmaceutical manufacturing. As a catalyst carrier, as a fluid for thermometric and thermostatic equipment, and as an herbicide for low-temperature polymerization.

Obsolete applications

Chloromethane was a widely used refrigerant, but its use has been discontinued. Chloromethane was also once used to produce lead-based gasoline additives (tetramethylated).

Chloromethane properties

  • Molar mass: 64.51 g/mol
  • Boiling point: 54.14°F (12.3°C)
  • Formula: C2H5Cl
  • Density: 920 kg/m³
  • ChemSpider ID: 6097
  • Classification: Hydrocarbon
  • Colors: Colorless gas


Inhalation of chloromethane gas produces central nervous system effects similar to that of alcohol intoxication. TLV is 50 ppm and in Mach only. Prolonged exposure may have a mutagenic effect.

Scroll to Top