Phenol, paraalkylation products with C12-rich branched olefins derived from propene oligomerisation, reaction products with sulphur monochloride and decene, reaction products with Benzoic acid, 2-hydroxy-,C14-18 alkyl dervis., polybutenyl benzenesulphonic acid, carbon dioxide and calcium hydroxide

Endpoint summary

Additional information

In the key study (2016 OECD 301B), EC 903-162-9 was shown to undergo biotic and abiotic degradation, but did not fulfil the criteria for ready biodegradability. Due to the test items low water solubility, silica gel was used to enhance the bioavailability to the inoculum, the study was also extended to 60 days to investigate the inherent degradation potential of the test item. A mean total of 62.6% degradation was achieved after 60 days. The average biotic and abiotic cumulative percent biodegradation for EC 903-162-9 were 17.4% and 45.2% respectively. Based on these findings it was concluded that the test item was not readily biodegradable.

In the supporting study, the test item, EC-903-162-9, was not readily biodegradable under the conditions of the test. A mean total of 25.5% degradation was achieved by Day 28. Therefore EC-903-162-9, was not readily biodegradable under the conditions of the test as it failed to achieve a transition from 10% to 60% degradation in a 10 day window during the 28 day test. The abiotic control data indicate that a significant proportion of the biodegradation recorded for EC-903-162-9 was a result of abiotic degradation; the acidification of the bioreactors on Day 28 did not result in the generation of CO₂ from the carbonate component of EC-903-162-9.

Although the supporting study was conducted to GLP standard and in accordance with OECD guideline 301B, the methodology used did not take account of the low water solubility of the test item, therefore the results are not considered indicative of the inherent biodegradation potential of the test item. As such the key study is considered to be more indicative of the inherent biodegradation potential of the test item.

It is concluded that the test item is not readily biodegradable, it does show degradation potential, the majority of which is abiotic given the high levels of inorganic carbon present in the substance. However, even using modifications to the standard protocol (extension to 60 days and silica gel) complete degradation was not achieved, illustrating that there are organic constituents within the UVCB substance that are not readily biodegradable.

No further degradation testing is proposed, this is in agreement with the specific rules of adaption text that is contained in column 2 section 9.2 Annex VIII of Regulation (EC) No 1907/2006, which states "Further biotic degradation testing shall be proposed by the registrant if the chemical safety assessment according to Annex I indicates the need to investigate further the degradation of the substance. The choice of the appropriate test(s) depends on the results of the chemical safety assessment." The CSA does not indicate the need for further degradation testing, therefore none is proposed.