Registration Dossier

Ecotoxicological information

Sediment toxicity

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
sediment toxicity: long-term
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:

Description of key information

Waiving according to the Integrated Testing Strategy for toxicity to sediment (ECHA, 2017; Endpoint specific guidance, Chapter R.7b, Section 7.8.14).

Key value for chemical safety assessment

Additional information

According to “Guidance on information requirements and chemical safety assessment Chapter R.7b: Endpoint specific guidance”, Section 7.8.14 Integrated Testing Strategy for toxicity to sediment (ECHA, 2017), the main property of a substance that triggers the assessment for the sediment compartment is the potential to adsorb or bind onto sediment. A log Kow of 3 should be used as trigger value for a sediment assessment. Available data for all main components of Tar acids, xylenol fraction (CAS 84989-06-0) demonstrate the log Kow to be below 3, i.e. xylenol-isomers: 2.09 to 2.42 (DEZA, 2010; EPA, 2010; Sangster, 1989); cresol-isomers: 1.94 to 1.98 (OECD SIDS, 2003; Sangster, 1989); ethyl-phenols: 2.09 to 2.58 (DEZA, 2010; Umeyama et al., 1971; Sangster, 1989), or trimethyl-phenols: 2.67 to 2.73 (Sangster, 1989). Thus, Tar acids, xylenol fraction (CAS 84989-06-0) exhibits low potential for adsorption to sediment (log Kow < 3). Furthermore, in accordance with Regulation (EC) No 1907/2006, Column 2 of Annex X, section 9, toxicity tests on sediment organisms do not need to be investigated if the outcome of the chemical safety assessment shows no indication of risk on sediment organisms from exposure to the substance in question. The PNEC sediment has been derived using the equilibrium partitioning method on the basis of available data for xylenol-isomers. Xylenol-isomers are the main constituents of Tar acids, Xylenol fraction (CAS 84989-06-0). Besides the PNEC freshwater, the Koc is the main input parameter for EPM calculation. As the log Kow values are very similar among all constituents of Tar acids, Xylenol fraction (CAS 84989-06-0) and consequently also Koc values the calculated PNECs for xylenol-isomers are considered representative. The risk characterization ratio (RCR) has demonstrated that there is no indication of risk i.e. PEC/PNEC sediment < 1 from current exposure conditions to the test substance. Furthermore, the substance is unlikely to pose a hazard to sediment organisms due to the absence of bioaccumulation potential (considering the low log Kow). Taking all the available information mentioned above into account long-term sediment tests with benthic species are not required.