Registration Dossier
Registration Dossier
Diss Factsheets
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 201-167-4 | CAS number: 79-01-6
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data

Biodegradation in water and sediment: simulation tests
Administrative data
Link to relevant study record(s)
- Endpoint:
- biodegradation in water: sediment simulation testing
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Published in peer reviewed literature, limitations in design and/or reporting, but adequate for assessment
- Principles of method if other than guideline:
- The depletion of trichloroethylene was studied in microcosms containing water and natural sediment ranging in composition from highly organic to a calcareous sedimentary rock. The depletion of trichloroethylene was followed by test material analysis.
- GLP compliance:
- not specified
- Oxygen conditions:
- anaerobic
- Inoculum or test system:
- natural sediment
- Details on source and properties of sediment:
- Organic muck was collected from the Everglades, a graminoid wetland that is the recharge basin for the Biscayne Aquifer in Southern Florida. The VB sand was obtained from a site that was previously contaminated by a trichloroethylene spill in Vero Beach (FL, USA). The rock was obtained from the Everglades near the muck collection site.
- Details on inoculum:
- Inoculum present in natural sediments
- Duration of test (contact time):
- 6 mo
- Initial conc.:
- 5 mg/L
- Based on:
- test mat.
- Parameter followed for biodegradation estimation:
- test mat. analysis
- Details on study design:
- Each microcosm was spiked to contain 5 mg/L of trichloroethylene with a solution of trichloroethylene in nitrogen-purged distilled water. The microcosms were spiked 2 weeks after construction to allow equilibration and oxygen depletion to occur inside the test and control bottles and thus simulate original conditions of the sample site. All microcosms and controls were allowed to incubate in the dark at 25 C for measured time periods up to 6 months. Replicate were constructed for each sampling period.
- Reference substance:
- other: none
- Key result
- % Degr.:
- 100
- Parameter:
- test mat. analysis
- Sampling time:
- 6 mo
- Key result
- Compartment:
- entire system
- DT50:
- 73.1 d
- Type:
- (pseudo-)first order (= half-life)
- Temp.:
- 25 °C
- Remarks on result:
- other: average for muck
- Key result
- Compartment:
- entire system
- DT50:
- 42.5 d
- Type:
- (pseudo-)first order (= half-life)
- Temp.:
- 25 °C
- Remarks on result:
- other: averge for sand
- Key result
- Compartment:
- entire system
- DT50:
- 90.3 d
- Type:
- (pseudo-)first order (= half-life)
- Temp.:
- 25 °C
- Remarks on result:
- other: rock
- Other kinetic parameters:
- first order rate constant
- Transformation products:
- yes
- No.:
- #1
- Evaporation of parent compound:
- not specified
- Volatile metabolites:
- not specified
- Residues:
- not specified
- Endpoint:
- biodegradation in water: sediment simulation testing
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- comparable to guideline study with acceptable restrictions
- Remarks:
- Non-GLP near guideline study, published in peer reviewed literature, notable restrictions in design and/or reporting but otherwise adequate for assessment
- Principles of method if other than guideline:
- Trichloroethylene was transformed in microcosms composed of aquifer materials. Microcosms consisted of natural uncontaminated sediments and groundwater bacteria. Biotransformation products were purge-trapped and analysed by GC equipped with electrolytic conductivity detectors.
- GLP compliance:
- no
- Radiolabelling:
- no
- Oxygen conditions:
- anaerobic
- Inoculum or test system:
- other: groundwater
- Details on source and properties of surface water:
- Distilled water was used
- Details on source and properties of sediment:
- Natural sediments were collected from uncontaminated sites in the Everglades
- Details on inoculum:
- Bacterial cultures from groundwater taken from a trichloroethylene spill site. These cultures were composed of mixed populations of aquatic or soil microorganisms.
- Duration of test (contact time):
- > 7 - < 8 wk
- Initial conc.:
- > 4 - < 5 µg/L
- Based on:
- test mat.
- Parameter followed for biodegradation estimation:
- test mat. analysis
- Details on study design:
- Sediments were thoroughly mixed and passed through a 6.35 mm sieve. Sediment microcosms were prepared by adding an equivalent of 4 g dry weight of muck or mud or 6 g dry weight of marl to 50-mL septum bottles and completely filling the bottles with distilled water.
Initial time (T0) microcosms were sampled immediately; all other microcosms were incubated at 25 C in the dark until analysis.
Control microcosms consisted of sediment and culture without trichloroethylene. Abiotic controls consisted of sediment and culture, but were autoclaved before spiking with trichloroethylene.
After spiking, the microcosms were sealed with PTFE-lined septa and shaken for 30 s to mix the contents.
Sampling was done at three periods: T0 (immediately after spiking), T1 (after 2-3 weeks) and T3 (after 7-8 weeks). - Key result
- Remarks on result:
- not measured/tested
- Transformation products:
- yes
- No.:
- #1
- No.:
- #2
- Details on transformation products:
- A maximum concentration of 167±6.4 µg/L of cis-1,2-dichloroethylene (#1) was observed after 2-3 weeks of incubation. The maximum concentration of trans 1,2-dichloroethylene (#2) was 4.26 µg/L after 7-8 weeks of incubation.
- Evaporation of parent compound:
- no
- Volatile metabolites:
- yes
- Residues:
- not measured
- Endpoint:
- biodegradation in water: simulation testing on ultimate degradation in surface water
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Published in peer reviewed literature, notable limitations in design and/or reporting, but adequate for assessment
- Principles of method if other than guideline:
- Degradation was examined in seawater under aerobic conditions
- GLP compliance:
- not specified
- Oxygen conditions:
- aerobic
- Inoculum or test system:
- natural water: marine
- Key result
- Remarks on result:
- other: detailed information not available, no biodegradation observed
- Transformation products:
- not specified
- Endpoint:
- biodegradation in water: sediment simulation testing
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- other: Published in peer reviewed literature, notable limitations in design and/or reporting, but adequate for assessment
- Principles of method if other than guideline:
- Sub-surface sediments were incubated with trichloroethylene (50 mg/l), and with either methanol or propane for 10-30 days.
- GLP compliance:
- not specified
- Radiolabelling:
- not specified
- Oxygen conditions:
- not specified
- Inoculum or test system:
- other: Sub-surface sediment
- Duration of test (contact time):
- 30 d
- Initial conc.:
- 50 mg/L
- Based on:
- test mat.
- % Degr.:
- 25
- Sampling time:
- 10 d
- Remarks on result:
- other: incubated in subsurface sediment with methanol
- % Degr.:
- 95
- Sampling time:
- 30 d
- Remarks on result:
- other: incubated in subsurface sediment with methanol
- % Degr.:
- 0
- Sampling time:
- 10 d
- Remarks on result:
- other: incubated in subsurface sediment with propane
- % Degr.:
- 45
- Sampling time:
- 30 d
- Remarks on result:
- other: incubated in subsurface sediment with propane
- Transformation products:
- not specified
Referenceopen allclose all
The depletion (i.e. the removal mechanism was not determined) of trichloroethylene in microcosms containing water and three types of natural sediment (muck, sand and rock) was studied. The organic carbon contents for the muck, sand and rock were 25%, 2% and < 1% respectively and the sand had already been exposed to trichloroethylene through a major spill from a storage tank. The muck and sand had similar depletion rates and the depletion in the rock microcosm was slower. The results suggest that depletion depends on the organic content of the sediment and the microbial biomass.
Reductive dechlorination was observed to be the first step in the biotransformation of trichloroethylene. Further dechlorination or other chemical transformations occurred because the products of reductive dechlorination reduced after attaining maximum concentrations.
Reductive dechlorination produced both isomers of 1,2 -dichloroethylene. The cis-isomer was always produced in greater concentration than the trans-isomer.
No degradation of trichloroethylene in seawater was observed under aerobic conditions
After 10 days incubation with methanol, 25% trichloroethylene was degraded and after 30 days 95% was degraded. After 10 days incubation with propane, 0% was degraded, and after 30 days 45% was degraded. Results are given in Table 1
Table 1 Anaerobic degradation of trichloroethylene
Test conditions |
Test results |
Reference |
Trichloroethylene (50 mg/l) incubated in subsurface sediment (10g) with methanol |
25% degradation after 10 days, 95% degradation after 30 days |
Phelps et al, 1988 |
Trichloroethylene (50 mg/l) incubated in subsurface sediment (10g) with propane |
0% degradation after 10 days, 45% degradation after 30 days |
Phelps et al, 1988 |
Description of key information
Within a weight of evidence approach it was concluded that TCE was not degraded in marine water under aerobic conditions.
The biotransformation by freshwater sediment microbiota seem to occur more readily under anaerobic conditions under specific conditions like co-substates.
Key value for chemical safety assessment
Additional information
A variety of information is available for TCE investigating the biodegradation in sediments under certain conditions. It can be deduced from available data that degradation is more pronounced under anaerobic conditions and in the presence of co-substates.
For example, Trichloroethylene can be degraded under aerobic conditions by a process of co-oxidation when other suitable co-substrates (methane, propane, toluene, phenol) are also present to support growth of the microorganisms and induce the formation of enzymes which due to their broad substrate specificity, can also degrade trichloroethylene.
Furthermore, there is extensive work which shows that under anaerobic conditions, trichloroethylene degrades by a process of reductive dehalogenation, resulting in the formation of lower chlorinated homologs as reaction products. Although metabolites are known to occur, the terminal product of reductive dehalogenation is ethylene.
From review of literature additional information is available supporting the conclusions above and provide more information on degradation process under specific conditions.
However, for assessment as a worst case EUSES degradation estimates calculated based on input parameter “not biodegradable” were used.
This is agreement with EU risk assessment (2004) and recently published EPA draft risk assessment (2020).
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
