Chloroform is primarily used in the production of refrigerants (e.g. chlorofluorocarbon (CFC)-22, fluorocarbon-22), in the production of plastics (especially vinyl chloride) and in the manufacture of other chemicals. Chloroform is used as an extraction solvent for fats, oils, greases, rubber, waxes, gutta-percha, resins, lacquers, floor polishes, artificial silk manufacture, gums and adhesives. It is utilised as an industrial solvent in the extraction and purification of some antibiotics, alkaloids, vitamins and flavours. It is used as a solvent in organic chemistry, in photography and in making dyes, drugs and pesticides. Other uses are as a dry cleaning agent to remove spots, as a fumigant and in fire extinguishers to lower the freezing temperature of carbon tetrachloride. Chloroform formulated with other ingredients is used to control screw worm in animals. Chloroform is steadily being replaced by less toxic solvents and may no longer be used in some of these applications. Its use as an inhaled anaesthetic during surgery has already been largely discontinued.
Substance name: Chloroform (trichloromethane)
CASR number: 67-66-3
Molecular formula: CHCl3
Synonyms: Trichloromethane, methyl trichloride, methane trichloride, formyl trichloride, methenyl trichloride, trichloroform, TCM, Freon 20, Refrigerant R20
Chloroform is a clear, colourless, volatile, non-flammable liquid with a pleasant, sweet odour which is detectable at ppm levels.
Melting Point: 64°C
Boiling Point: 62°C
Specific Gravity: 1.50
Vapour Density: 4.1
Fire may cause closed chloroform containers to explode.
Chloroform is slightly soluble in water. It is miscible with alcohol, benzene, petroleum ether, carbon tetrachloride, carbon disulfide and oils. Chloroform reacts vigorously with strong caustics, strong oxidants, chemically active metals such as aluminium, lithium, magnesium, sodium or potassium, and acetone, causing fire and explosion hazards. It can attack plastic, rubber and coatings. Chloroform decomposes slowly under the influence of light and air. It also decomposes on contact with hot surfaces, flames or fire, forming irritating and toxic fumes which consist of hydrogen chloride, phosgene and chlorine.
The National Pollutant Inventory (NPI) holds data for all sources of chloroform emissions in Australia.
Exposure to chloroform occurs mainly through breathing or skin contact. Exposure to the vapour can irritate the eyes, nose and throat. Lower concentrations of chloroform can cause dizziness, fatigue, light-headedness, nausea, confusion and headaches. Higher levels may induce anaesthesia with changes in respiratory rate, cardiac effects (e.g. irregular heart beats), gastrointestinal effects (e.g. nausea and vomiting) and effects on the liver and kidneys. Exposure to very high levels can result in death. A fatal oral dose of chloroform may be as low as 10 mL (14.8 g) with death due to respiratory or cardiac arrest. Breathing chloroform or ingesting chloroform over long periods of time may damage liver (such as hepatitis and jaundice), kidneys, skin and central nervous system (such as depression and irritability). Skin contact with the liquid can cause a rash or a burning feeling. Repeated skin contact may produce dermatitis. Absorption through intact skin occurs rapidly. The liquid can cause severe eye burns. Chloroform is a probable carcinogen (agent that causes cancer) and it may be teratogenic (may cause foetal abnormalities).
Entering the body
Chloroform can be absorbed into the body by inhalation, through the skin and by ingestion.
Exposure to chloroform can occur mainly in the workplace of industries that use chloroform. Inhalation and skin contact are the most likely exposure routes. Ingestion is unlikely. The general public may be exposed to trace amounts of chloroform by drinking chlorinated water, by eating food or drinking beverages where tap water containing chloroform is used during production processes or by swimming in pools treated with chlorine.
Workplace exposure standards
Safe Work Australia sets the workplace exposure standard for chloroform through the workplace exposure standards for airborne contaminants:
- Maximum eight hour time weighted average (TWA): 2 parts per million (10 mg/m3)
These standards are only appropriate for use in workplaces and are not limited to any specific industry or operation. Make sure you understand how to interpret the standards before you use them.
Drinking water guidelines
The Australian Drinking Water Guidelines include the following guidelines for acceptable water quality:
- Maximum of 0.25 milligrams per litre of water in total for all trihalomethanes for health purposes.
Chloroform may be hazardous to the environment. Chloroform in water has moderate acute and chronic toxicity to aquatic life. The concentration of chloroform in fish tissues is expected to be somewhat higher than the average concentration of chloroform in the water from which the fish is taken. It is non-persistent in natural waters with a half-life of less than two days. Chloroform can cause damage to various plants including brittleness in roots and chromosomal damage. No data are available on the short-term effects of chloroform on birds or land animals and no data are available on the long-term effects of chloroform to plants, birds, or land animals.
Entering the environment
Chloroform can be transported in air as vapour and dissolved in water.
Where it ends up
Chloroform evaporates easily into the air where it eventually breaks down to other toxic chemicals such as phosgene and hydrogen chloride. This is a slow process. Chloroform dissolves in water from where it can evaporate to air or can break down to other chemicals. The vast majority of chloroform will eventually end up in air and only a small percentage will end up in water. Chloroform is not bound to soil and can travel through the soil to the ground water. Due to the absence of light and air, chloroform may last a long time in ground water.
No national guidelines.
Chloroform may enter the environment from a number of sources, including industrial effluent, municipal waste treatment plant discharges, hazardous waste sites, sanitary landfills and spills.
Diffuse sources, and industry sources included in diffuse emissions data
Chloroform can be formed as a result of the chlorination of naturally occurring organic materials found in raw water supplies. Hence, water treated with chlorine (drinking water, swimming pool) may be contaminated with trace amounts of chloroform.
There are no natural sources for chloroform.
There are no mobile sources for chloroform.
There are no consumer products that contain chloroform.
Sources used in preparing this information
- Agency for Toxic Substances and Disease Registry (ATSDR), ToxFAQs (September 1997), Chloroform (accessed, June, 1999)
- ChemFinder WebServer Project (1995), Chloroform (accessed, June, 1999)
- Environmental Health Center (a division of the National Safety Council) Environment Writer - Chemical Backgrounders (July 1, 1997), Chloroform (accessed, June, 1999)
- Integrated Risk Information System (IRIS, January 31, 1987), Chloroform (accessed, June, 1999)
- International Programme on Chemical Safety and The Commission of the European Communities (IPCS CEC 1993), International Chemical Safety Cards, Chloroform (accessed, June, 1999)
- National Environment Protection Council (1998), National Environment Protection Measure for the National Pollutant Inventory. (accessed, March, 1999)
- Technical Advisory Panel (1999), Final Report to the National Environment Protection Council.
- Open Data Solutions, EPA factsheets for regulated toxic chemicals (January, 1989), Chloroform (accessed, June, 1999)
- US EPA (Environmental Protection Agency) TTNWeb (Technology Transfer Network) and US OAQPS (Office of Air Quality Planning & Standards) UATW (Unified Air Toxics Website), Health Effects Notebook for Hazardous Air Pollutants (May 19, 1998), Chloroform (accessed, June, 1999)
- Worksafe Australia (1996), Hazardous Substances Database, Chloroform (accessed, June, 1999)
- Safe Work Australia, Workplace exposure standards for airborne contaminants, accessed June 2021.
- National Health and Medical Research Council (NHMRC), Australian Drinking Water Guidelines (2011) - Updated October 2017, accessed May 2018