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: 222-182-2 | CAS number: 3380-34-5
Biodegradation in water: screening tests
Administrative data
Link to relevant study record(s)
Description of key information
Triclosan is not readily biodegradable (according to OECD criteria), but inherently biodegradable.
Its metabolite methyl-triclosan (CAS 4640 -01 -1) is also inherently biodegradable.
Key value for chemical safety assessment
- Biodegradation in water:
- inherently biodegradable
Additional information
The ready biodegradability of Triclosan was tested by several guideline studies. In a study following OECD guideline 301 B the O2 consumption of activated sludge fed with 10 or 20 mg/l test substance was tested. After 28 days a degradation rate of 18 % at a test substance concentration of 20 mg/l was detected. At a test substance concentration of 10 mg/l 37 % of Triclosan were degradaded after 28 days (Ciba-Geigy 1989). Comparable results were derived in a study conducted according to OECD guideline 301 C. Based on O2 consumption a degradation rate of 0 % was determined after 28 days (Ciba-Geigy 1990).
In guideline study on inherent biodegradability according to OECD 302 B a elimination rate of 99.4 % was detected after 14 days of incubation (Ciba-Geigy 1999). Thus the substance is inherently biodegradable. This result is supported by a study on mineralisation of Triclosan in a continuous activated sludge system (CAS). The substance was added continously to activated sludge for 1 ½ month. The degradation rate was determined by analysing the Triclosan concentration after ca. 50 days. The removal rate was 98.2 - 99.3 % (Ciba Specialty Chemicals 1998). In a second CAS test the concentration of Triclosan was constantly increased from 40 µg/l to 200 µg/l. A degradation rate of 75 -88 % was determined by radiochemical measurement (Procter & Gamble 1992). The results are supported by a third CAS test. The test run for 71 days. Based on CO2 evolution a degradation rate of 80 - 98.5 % was recorded (Federle et al. 2002). Under anaerobic conditions less than 10 % degradation were observed (Colgate-Palmolive 1994).
Methyltriclosan (CAS 4640 -01 -1) is regarded as one of the metabolites of triclosan. In an enhanced OECD 301 B study under GLP, methyltriclosan was not readily biodegradable, but proved to be inherently biodegradable (BASF SE; 2012; project no. 22G0533/10G059).
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.
