Registration Dossier
Registration Dossier
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: 200-262-8 | CAS number: 56-23-5
Phototransformation in air
Administrative data
Link to relevant study record(s)
Description of key information
The atmospheric lifetime of CTC is estimated to be 34 years.
Key value for chemical safety assessment
- Half-life in air:
- 34 yr
Additional information
CTC is susceptible towards indirect photolysis by hydroxyl radicals in the troposphere (its estimated tropospheric half-life exceeds 330 years). Ultimately it diffuses upward into the stratosphere where it may be photodegraded (185-225 nm) to form the trichloromethyl radical and chlorine atoms.
Direct photolysis under stratospheric conditions is very efficient and the DT50 values range in the order of minutes. However the migration time to the troposphere is very long and the migration time limits the dissipation. On the other hand the direct photolysis of CTC is involved in global warming by ozone depletion.The rate of photodissociation begins to become important at altitudes >20 km, and increases as altitude increases. Estimates of the atmospheric lifetime (the overall persistence of CTC in the troposphere and the stratosphere combined) range from 30 to 100 years, with 34 +/- 5 years being the most recently refined value.
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.
