Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

The potential for biodegradation of Di-Trimethylolpropane was assessed in two studies with further supportive information coming from a Japanese NITE report.

 

A ready biodegradability test was performed on Di-Trimethylolpropane according to ISO and OECD Test Guidelines.

The test substance did not meet the criteria for ready biodegradability over 28 days, and therefore cannot be considered readily biodegradable.

However, when incubated further (for up to 42 days), the test material passed the pass level criterion for inherent biodegradability. As such the substance is considered to be inherently biodegradable.

 

A further biodegradation study was conducted in accordance with SS-EN 29 888:1993 "Zahn-Wellen Test", which is identical to OECD method 302B (1992). Di-Trimethylolpropane was found to be biodegradable under the conditions applied during the test. Biodegradation commenced without any lag time.

Removal of DOC for Di-Trimethylolpropane reached over 90% by the end of the 28 day study period. The result of this study confirmed the classification of Di-Trimethylolpropane as inherently biodegradable. The pass level of 70% was achieved in 7 days.

 

The result of a biodegradation test on Di-Trimethylolpropane was posted on the National Institute of Technology and Evaluation website (www.safe.nite.go.jp). Di-Trimethylolpropane was found to be non-biodegradable under the conditions applied in the test. This can be taken as supportive evidence that Di-Trimethylolpropane is not readily biodegradable.

 

Despite the fact that Di-Trimethylolpropane was not classified as readily biodegradable its classification as inherently biodegradable suggests that it will be significantly removed by biological processes in the STP. It is thus expected that Di-Trimethylolpropane will not persist in soil, sediment or in the environment generally.

According to Column 9.2 of REACH Annex IX, further degradation testing (including simulation testing in appropriate media, e.g. water, sediment or soil) shall only be considered if it is demonstrated in the chemical safety assessment (according to Annex I) that it is necessary to further investigate the degradation of the substance and its degradation products. Available experimental ecotoxicity test data has demonstrated very low ecotoxicity of di-trimethylolpropane (fish 96 hour LC50: >1000 mg/L; aquatic invertebrate 48 hour EC50: 3560 mg/L; algae 72 hour EC50: >1000 mg/L). No adverse effects were observed at the highest recommended concentrations tested, thereby indicating that no hazard has been identified and that PNEC values would not need to be derived (ECHA, 2011) (although for completeness, PNECs have been derived regardless). Moreover, the substance does not fulfil the criteria for being regarded as PBT or vPvB, nor is direct release of the substance into the environment anticipated. Consequently, according to the chemical safety assessment performed according to Article 14(3) in connection with Annex I section 3 (Environmental Hazard Assessment), no environmental risk assessment is required under REACH. It is therefore not considered necessary to further investigate the degradation of di-trimethylolpropane or its degradation products in water and sediment or soil, as per Column 9.2 of REACH Annex IX.

Additional information

ECHA, 2011. ECHA Guidance on information requirements and chemical safety assessment Part B: Hazard Assessment. Helsinki: ECHA.