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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

Two reliable ready biodegradability tests are available. In both tests, TMAOH was ready biodegradable.

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

A ready biodegradability test was carried out with 25% TMAOH according to to OECD301 B and GLP (Noack, 2001).

The concentration of the test substance at the beginning of the test was 90 mg/L (corresponding with 22.5 mg TMAOH/L).

Based on the results, it can be concluded that TMAOH is readily biodegradable.

A ready biodegradability test was carried out with 27.5% TMAOH according to to OECD301 B and GLP (CERI, 2002).

The concentration of the test substance at the beginning of the test was 100 mg/L (corresponding with 27.5 mg TMAOH/L).

Based on the data in the SIDS, the test substance shows more than 90% degradation within 14 days, measured according to different methods. The substance TMAOH is therefore considered to be ready biodegradable.

Under anaerobic conditions a rapid biodegradation is possible as well:

TMAOH biodegradation was studied in a batch test with sludge from an Upflow Anaerobic Sludge Blanket (UASB) treating TFT-LCD waste water at concentrations varying from 500 - 2000 mg/L (Hu et al., 2010). The TMAOH concentrations were determined by ion chromatography at regular intervals. For all concentrations 100% biodegradation was observed within 10 hours. The total volume of accumulated methane gas production.

Although both ready biodegradability studies were carried out in accordance with OECD guidelines and GLP and have similar results, the study from Noack (2001) was selected as a key study because the original study report was available and thus more details could be evaluated, whereas the study from CERI (2002) had to be summarised and evaluated based on the IUCLID summary from the OECD SIDS of TMAOH (CERI, 2006). Furthermore, in the study from Noack (2001) a toxicity control was included, whereas in the study from CERI (2002), this was not the case.