Registration Dossier

Environmental fate & pathways

Phototransformation in water

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Link to relevant study record(s)

Description of key information

No specific photolysis studies are available for submission. The estimation for elimination by photolytic reactions from water are thought to be negligible however the material will readily volatilise from water and has an estimated air water partition coefficient (Kaw) of -0.13 - -0.17.

Key value for chemical safety assessment

Additional information

In the 1996 UK review it is noted that the material is fairly resistant to photolysis with an upper half live estimate of six years. The results of studies submitted in the photodegradation section of this dossier indicate that the half live due to hydroxyl radical removal in the upper atmosphere is estimated to be 3.8 - 6.0 years. The UK review attributes the bulk of atmospheric release to metal cleaning activities and similar uses which are now severely restricted following implementation of the Montreal Protocol. This review also estimates that in 1988 approximately 6% of total production was released into the environment of which 0.2 - 0.3% was released during manufacture. This resulted in estimates of 0.15 - 0.17ppb in the atmosphere. As 1,1,1-trichloroethane is now restricted to use as a transported intermediate releases into the atmosphere would be expected to have radically reduced.