Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Adsorption / desorption

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Koc at 25 °C = 59.43, log Koc = 1.78 (ACD/LogD Suite Program, Version 12)

Key value for chemical safety assessment

Additional information

The structure of the substance shows a possibility of keto-enol tautomerism. It can be expected that under environmental conditions the major part of the molecules of the substance are existent in the keto form and only a minor, probably negligible part in the enol form. For the natural, undissociated keto form, the Koc is stated as 59.43 at 25 °C (log Koc 1.78) as calculated with ACD/LogD Suite Program, Version 12 (2011-00008-DKB) and therefore TMT can be considered as a substance with low adsorption potential.

A non-guideline study investigated the removal of the excess of TMT 15 by activated sludge adsorption as TMT is used as precipitating agent in a water treatment plant (95 -0178 -DKP). The results showed that a high adsorption potential to sewage sludge could be observed for TMT 15 at test conditions, the removal rate raised with decreasing concentration of TMT 15. However, the test did not investigate the adsorption kinetics. TMT readily forms insoluble complexes with transition and main group metals in aqueous solution. Removal rate of exess TMT in waste water by activated sludge therefore is considered to be a more complex process in aqueous solution than adsorption. The calculation of Koc refer to the adsorption in soil, in contrast activated sludge is characterised by a significant higher amount of organic carbon. Furthermore, the adsorbing surface of activated sludge is much higher than in soil. Therefore, high removal rate of TMT by activated sludge in SPT is not a standard criterion for assessment of soil adsorption property.

Since there is no experimental data available, the assessment on soil adsorption/desorption has been perfomed based on the calculation of the Koc. According to the technical guidance document, this QSAR method is considered to be scientifically acceptable.

Other adsorption coefficient indicated as dimensionless:
- other: Koc ,59.43 at the temperature 25.0°C