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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

At equilibrium, greater than 99 % of environmental chloroform is expected to be present in the atmosphere, where it can undergo slow degradation by indirect photolytic reaction with OH-radical. The half-lives for this reaction range from approximately 20 to 120 days. Because of its water-solubility, atmospheric chloroform may be removed by wet deposition. However, extensive revolatilisation from soils and surface waters is likely. Hydrolysis of chloroform is a negligible process with regard to its environmental degradation. But the presence of dissolved organic matter may accelerate the degradation by indirect photolysis of chloroform in surface waters. No significant biodegradation is observed in surface waters or soils under aerobic conditions. Specific anaerobic conditions may favour the biodegradation of chloroform in these media. Also, biodegradation of chloroform occurs in methanogenic sediments. The low affinity of chloroform for organic carbon (low KOC) and for lipids (low KOW) results in weak adsorption of the substance to soils or sediments. Chloroform thus may pass readily through sandy soils or sediments and may reach the groundwater. The low values for KOC and KOW indicate that chloroform is likely to have a low potential for bioaccumulation.

Abiotic degradation

Based on the physicochemical properties of chloroform it can be assumed that chloroform will be mainly present in the atmosphere when released to the environment. The available data indicate that chloroform present in the atmosphere tends to undergo at least slow degradation; the reaction of the compound with OH-radical seems to represent the most efficient removal process. According rate constants for the reaction of chloroform with OH produce atmospheric half-lives between about 20 and 120 days (mean half-life of approximately 70 days).

The hydrolysis of chloroform may be neglected, as the associated half-lives are in the range of several years at pH 9 and more than 1000 years at pH seven. However, the presence of dissolved organic matter may accelerate the degradation of dissolved chloroform resulting in an aquatic half-life of approximately 25 days, which is in the same range as that for reaction with OH-radical.

In conclusion, chloroform can be regarded as relatively resistant against abiotic degradation in the atmosphere and aquatic environment. Chloroform thus may be subject to transport over relatively long distances.

Biotic degradation

No significant biodegradation of chloroform in surface waters was observed under aerobic, environmental conditions. Chloroform dissolved in water was only degraded under anaerobic conditions in specifically constructed bio-reactors.

Chloroform is degraded in anaerobic sediments. The half-lives observed in tests carried out with natural methanogenic sediments ranged from 2 to 37 days, and realistic values were around 15 days. Similar tests with sandy sediments exhibiting low contents of organic carbon showed that no degradation of chloroform was achieved, which was not due to the absence of methanogenic bacteria but due to the conditions present in this type of sediment.

Degradation tests performed with soils indicated that chloroform is only degraded by certain methane-utilising bacteria under special aerobic conditions. In general, it was assumed that no significant biodegradation of chloroform occurred in soils.

Degradation rate in water: 0 per day

Degradation rate in sediment: 0.046 per day

Degradation rate in soil: 0 per day

Degradation rate in air: 0.01 per day