Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Stability

For evaluating the stability of the test substance (Amber Core, P#620), two valid studies according to the Directive 84/449/EEC Part C Method C.07, performed under GLP are available. The abiotic degradation of Amber core was assessed in two parts: the results of the preliminary study (supporting study) were provided in the first report (Sunakawa, 1992) and the results of the definitive study (key study) were provided in the second report (Sunakawa, 1994). In the preliminary study (Sunakawa, 1992), the results indicate that a 25°C, Amber Core possesses a half-life between 1 day and 1 year at pH 4, 7 and 9. This indicated the need for further testing at pHs 4, 7 and 9 using the extended tests as described in the Directive. For the definitive study (Sunakawa, 1994), the hydrolysis reaction of Amber core at 25°C and pH 4 occurred with a half-life of 216 hours (9 days). At pH 7 and 25°C, the hydrolysis reaction of Amber core had an estimated half-life of 648 hours (27 days) and at pH 9 and 25°C, at an estimated half-life of 609 hours (25 days). Taking the longest half-life for hydrolysis into consideration, the half-life of 648 hours, equivalent to 27 days at 25°C and pH 7 was used as the key value for chemical safety assessment.

Biodegradation

For evaluating the biodegradation of the test substance, one study according to the OECD Guideline 301C (modified MITI Test (I))

performed under GLP, is available on the biodegradability of Amber Core (P#620). The concentration of test substance was 100 mg/L, the concentration of activated sludge was 30 mg/L and the cultivating duration was 28 days. The measurement of biochemical oxygen demand (BOD) was performed and the results show that the percentage biodegradation of the test substance was 3% on the average. Amber Core was not biodegraded under these test conditions.

Bioaccumulation

For evaluating the bioaccumulation of the test substance, one study is available on Carp (Cyprinus carpio). This study was performed in a flow through system under GLP and according to the "Method for Testing the Degree of Accumulation of Chemical Substances in Fish Body" stipulated in the "Testing Methods for New Chemical Substances" (July, 1974) and is based on OECD Guideline 305C (May, 1981).

An acute toxicity test was performed before the bioaccumulation test. This preliminary test result for 48 -hour LC50 (=9.95 mg/L) was used to decide on the test concentrations of the test substance in the bioaccumulation study. Two test medium concentration levels were used: 0.050 mg/L and 0.0050 mg/L. The temperature of test water was maintained at 25 +/- 2°C with concentrations of dissolved oxygen in test tank comprised between 6.4 and 7.8 mg/L (corresponding to >60% saturation). 15 fish were used in Level 1 and 2 and 5 fish were used in control (the control was set as a blank test). The duration of exposure was 8 weeks. 2 peaks on the mass fragmentogram were detected by GC-MS. The peaks were named peak A and B in the elution order respectively. The concentrations of test substance were analyzed by GC-MS. BCFs of the test substance were estimated to have reached equilibrium after 8 weeks. The bioaccumulation potential of test substance in carp was an approximately similar value at both levels. However, to consider the worst case, the value used for chemical safety assessment was the highest BCF obtained: 173.

Furthermore, the partition coefficient of Amber Core was estimated using a QSAR calculation and the corresponding mean of 3.81 was retained as key value. Additionally, to provide supplementary evidence, the bioconcentration factor was also estimated using QSAR calculations. With EPI Suite – BCFBAF v3.01, the BCF was comprised between 218.8 L/Kg and 304.1 L/Kg. With the CAESAR model, the BCF was estimated to be 27 L/Kg. It is assumed that the affinity of the substance for the lipids of an organism is insufficient for it to be considered bioaccumulative.

Transport and distribution

For evaluating the transport and the distribution of the test substance, a study according to the OECD draft document TGP/9475 and the requirements of the Annex to European Commission Directive 92/69/EEC to GLP, is available. An attempt was made to determine the log Koc experimentally using HPLC. However no well defined response for the Amber Core (P#620) was obtained and the log Koc was estimated using a PC KOC computer program, Version 1.21, Syracuse Research Corporation. The estimated Log10Koc was 1.80 and the equivalent Koc was 63.1.