Chlorotrifluoroethylene

Distribution modelling

Administrative data

Endpoint:

distribution modelling

Type of information:

calculation (if not (Q)SAR)

Remarks:

Migrated phrase: estimated by calculation

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Well documented and published methodology.

Data source

Reference

Reference Type:

other: Software

Title:

EQC Model Version 2.02

Author:

The Canadian Centre for Environmental Modelling and Chemistry

Bibliographic source:

EQC Model Version 2.02, The Canadian Centre for Environmental Modelling and Chemistry, May 2003. http://www.trentu.ca/academic/aminss/envmodel/models/EQC2.html

Materials and methods

Model:

calculation according to Mackay, Level III

Calculation programme:

EQC Model Version 2.02

Release year:

2 003

Media:

other: soil- air- water- sediment

Test material

Test material information

Constituent 1

Reference substance name:

Chlorotrifluoroethylene

EC Number:

201-201-8

EC Name:

Chlorotrifluoroethylene

Cas Number:

79-38-9

Molecular formula:

C2ClF3

IUPAC Name:

1-chloro-1,2,2-trifluoroethene

Test material form:

other: gas

Details on test material:

Test material: the model is applied to the pure substance.

Study design

Test substance input data:

Molar mass: 116 g/mol
Data temperature: 20°C
Water solubility: 380 g/m3
Vapour pressure: 612000 Pa
Log Kow : 1.65
Melting point: -158°C

Results and discussion

Percent distribution in media

Air (%):

100

Water (%):

0

Soil (%):

0.002

Sediment (%):

0

Any other information on results incl. tables

The EQC Fugacity III Model clearly shows that all the CTFE released to atmosphere remains in this compartment. The rates of transfer to soil, water and sediments are reduced and only negligible amounts of the total emission remian in these media.

Most of the very reduced amount of CTFE that partitions into water then tends to come back into air becuse of intermedia exchange and the rest is removed by advection.

CTFE is a volatile gas at ambient conditions with a slight water solubility, so it is not expected to partition into water.

Applicant's summary and conclusion

Conclusions:

CTFE released to atmosphere remains in this compartment. The rates of transfer to soil, water and sediments are reduced and only negligible amounts of the total emission remain in these media. Most of the very reduced amount of CTFE that partitions into water then tends to comes back into air because of intermedia exchange and the rest is removed by advection.

Executive summary:

In order to understand the environmental fate of chlorotrifluoroethylene (CTFE) the EQC Fugacity III Model has been applied (Version 2.02, The Canadian Centre for Environmental Modelling and Chemistry, May 2003). The EQuilibrium Criterion or EQC model is based on an evaluative multimedia model. Three degrees of complexity are treated in the EQC, particularly, levels I and II assume thermodynamic equilibrium is achieved; level II also include advective and reaction processes. Level III is a non-equilibrium, steady-state assessment of the chemical fate of the environmnet.

The results of Level III Model, which describe a situation more complex and realistic of then previous models, are here presented.

The physico-chemical properties requested by this model are the following:

- water solubility: 380 g/m3

- vapour pressure: 612000 Pa

- log Kow: 1.65

- melting point: -158°C

As input parameter a reaction half-life of about 96 hours has been entered, too.

Since in case of accidental emission CTFE is expected to be released only in air, an emission rate of 1000 kg/h has been assumed in this compartment.

The EQC Fugacity III Model clearly shows that the whole amount of CTFE released to atmosphere remains in this compartment. The rates of transfer to soil, water and sediments are reduced and only negligible amounts of the total emission remain in these media.

Most of the very reduced amount of CTFE that partitions into water then tends to comes back into air because of intermedia exchange and the rest is removed by advection.