Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Biodegradation: The substance was determined to be readily biodegradable using the CO2 evolution method (OECD 301 B, EU Method C.4-C and OCSPP 835.3110).

Adsorption coefficient: The adsorption coefficient of the test item was determined by the HPLC method to be > 4.27 x 10E05 with Log10 Koc > 5.63 (OECD 121 and EU Method C.19).

Additional information

Abiotic degradation; Hydrolysis

The study does not need to be conducted because the substance is readily biodegradable.

Biodegradation

A key study was performed to assess the ready biodegradability of the test item in an aerobic aqueous medium. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (1992) No. 301B, "Ready Biodegradability; CO2 Evolution Test" referenced as Method C.4-C of Commission Regulation (EC) No. 440/2008 and US EPA Fate, Transport, and Transformation Test Guidelines OCSPP 835.3110 (Paragraph (m)).

The test item, at a concentration of 10 mg carbon/L, was exposed to activated sewage sludge micro-organisms with mineral medium in sealed culture vessels in the dark at temperatures of between 22 and 24 °C for 28 days. 

 

Following the recommendations of the International Standards Organisation (ISO 10634, (1995)), the test item was dissolved in an auxiliary solvent prior to being adsorbed onto a filter paper and subsequent dispersal in test media. Using this method, the test item is evenly distributed throughout the test medium and the surface area of test item exposed to the test organisms is increased thereby increasing the potential for biodegradation.

 

The biodegradation of the test item was assessed by the determination of carbon dioxide produced. Control solutions with inoculum and the reference item, sodium benzoate, together with a toxicity control were used for validation purposes.

 

The test item attained 73% biodegradation after 28 days and satisfied the 10-Day windowvalidation criterion, whereby 60% biodegradation must be attained within 10 days of thebiodegradation exceeding 10%. The test item can therefore be considered to be readilybiodegradable under the strict terms and conditions of OECD Guideline No. 301B.

Adsorption coefficient

Adsorption coefficient was determined using the HPLC screening method, designed to be compatible with Method C.19 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001.

The test utilised a High Performance Liquid Chromatograph and a commercially available cyanopropyl reverse phase HPLC column containing lipophilic and polar moieties was used. The dead time was determined by measuring the retention time of formamide (purity quoted by supplier: 99.94%) at 820 mg/L in methanol:water (55:45). Solutions of reference standards were prepared in methanol and test item (0.1018 g) was diluted to 10 mL with tetrahydrofuran to give a concentration of 10.2 g/L

 

The adsorption coefficient of the test item was determined to be > 4.27 x 10E05 with Log10 Koc > 5.63.