Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Abiotic degradation; Hydrolysis

The test item as a whole was expected to be essentially insoluble in water. Therefore the test solution concentration required to dissolve all the components (less than half the water solubility) would be impractically low and a sufficiently sensitive analytical method was not available. The test item is a complex mixture, to which the test method is not ideally suited because each component that is unstable is likely to have its own hydrolytic rate. Furthermore, the main functional groups within the components of the test item are an ester and an amine. Although esters usually hydrolyse readily, especially in alkaline solutions, the test item components may have a significantly reduced hydrolytic rate due to them being essentially insoluble in water. The amine group will be stable. There is also a small amount of amide and alcohol groups. Amides are more hydrolytically stable than the ester, whilst the alcohol will be hydrolytically stable. Overall, these issues make hydrolysis testing unfeasible and testing was not carried out using Method 111 of the OECD Guidelines for Testing of Chemicals (13 April 2004) and Method C.7 Abiotic Degradation, Hydrolysis as a Function of pH of Commission Regulation (EC) No 440/2008 of 30 May 2008.

Biodegradation

A 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 18 to 23 °C for 28 days.

The biodegradation of the test item was assessed by 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 63 % biodegradation after 28 days and can therefore be considered to be readily biodegradable. The test item failed to meet the 10-Day window validation criterion, whereby 60% biodegradation must be attained within 10 days of the biodegradation exceeding 10%. However, in accordance with the Revised Introduction to the OECD Guidelines for Testing of Chemicals, (2006), if testing on a complex mixture is performed and it is anticipated that a sequential biodegradation of the individual structures takes place, then the 10-Day window should not be applied to interpret the results of the test.

Adsorption / desorption coefficient (Koc)

The test item was investigated using the HPLC screening method designed to be compatible with Method C.19 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 adsorption coefficient was determined to be over the range 7.76E04 to > 4.27 E05 with Log10 Koc determined to be 4.89 to > 5.63.