Registration Dossier

Environmental fate & pathways

Distribution modelling

Currently viewing:

Administrative data

Endpoint:
distribution modelling
Type of information:
(Q)SAR
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The calculation was based on the Mackay Level 1 distribution model. This model is widely accepted as reasonably reliable and therefore attracts a reliability assessment value of 2.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1999

Materials and methods

Model:
calculation according to Mackay, Level I
Calculation programme:
Aquatic marine environment specifically for North Sea conditions. Th e ENVCLASS software distributed by the "Nordic Council of Ministers" was used to determine the ultimate distribution in environment
Release year:
1 990
Media:
other: water, air,sediment.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
none provided

Study design

Test substance input data:
- Molar mass: 133.4
- Data temperature:20 C
- Water solubility: 1.55g/L at 20C
- Vapour pressure: 13300
- log Kow:2.46
- Sediment - water partition coefficient: 7.09
- Melting point: -33C
- Boiling point: 73-74C at 1013Pa
- Decomposition temp: =/>100C
- Koc: 2.2
- Density: 1.34 at 20C

Results and discussion

Percent distribution in media

Air (%):
99.7
Water (%):
0.25
Soil (%):
0.01
Sediment (%):
0.01

Any other information on results incl. tables

The results from the tables above show that the bulk of 1,1,1-trichloroethane released into the environment will be present in air. Values in soils and sediments are extremely low and in the case of sediment the reviewers suggest that no further work is required in this area.

Applicant's summary and conclusion

Conclusions:
The authors conclude that although 1,1,1-trichloroethane is not perceived to be a problem in the marine environment it is persistent in the atmosphere and restrictions for use as feedstock or essential use are restricted under the 1996 Montreal Protocol.
Executive summary:

The Mackay level 1distribution model is a useful guide to how a specific compound will partition between the 4 environmental compartments. the results of the model showed that in the case of trichloroethane the bulk of the material ended up in the air with approximately 0.25% in the aquatic environment and less than 0.01% in soil and sediment. The conclusions of the authors are that for practical purposes soil and sediments can be discounted as compartments of concern in the environmental fate of 1,1,1-trichloroethane.