Registration Dossier

Administrative data

Endpoint:
sediment toxicity: long-term
Study period:
maximum of 65 days
Data waiving:
other justification
Justification for data waiving:
other:

Data source

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 218 (Sediment-Water Chironomid Toxicity Test Using Spiked Sediment)
Principles of method if other than guideline:
The substance Cashew Nutshell Extract, Decarboxylated, Distillation Residue (Distilled Residue Grade) has a log Kow = >6.2 and because it exceeds the threshold of log Kow of 3 it is considered to have the potential to sorb to particulate matter including bed sediments. On this basis for any fraction either passing through the STP or potentially entering a surface water directly, it will be degraded within a short period of time limiting the likely sediment concentrations.

However the risk assessment suggests that there may be a remaining risk to sediment dwelling invertebrates. This perceived risk may a consequence of a rather precautionary PNEC which has been derived using the Equilibrium Partitioning approach in the absence of experimental data.

In order to refine the PNEC is proposed to carry out a long term toxicity test to invertebrates rather than carrying out a short term toxicity test. This is consistent with Column 2 of REACH Annex X which states that “Long-term toxicity testing shall be proposed by the registrant if the results of the chemical safety assessment indicates the need to investigate further the effects of the substance and/or relevant degradation products on sediment organisms. The choice of the appropriate test(s) depends on the results of the chemical safety assessment”

It is proposed that the study is carried out according to OECD Test Guideline 218 “Sediment-Water Chironomid Toxicity using Spiked Sediment” and to GLP. This study will assess the effects of prolonged exposure of Cashew Nutshell Extract, Decarboxylated, Distilled (Distilled Grade) (with read-across to Distilled residue Grade) to the sediment-dwelling larvae of the freshwater dipteran Chironomus sp. First instar chironomid larvae will be exposed to at least five concentrations of the test chemical in sediment - water systems. The test substance will be spiked into the sediment and first instar larvae will be subsequently introduced into test beakers in which the sediment and water concentrations have been stabilised. Chironomid emergence and development rate will be measured at the end of the test. The maximum exposure duration is 28 days for C. riparius, C. yoshimatsui, and 65 days for C. tentans. Larval survival and weight may also be measured after 10 days if required (using additional replicates as appropriate). The study report will include the development time and the total number of fully emerged midges (sex and number are recorded daily), the observation of any abnormal behaviour the number of visible pupae that have failed to emerge and any egg masses deposition.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in test report): Cashew Nutshell Extract, Decarboxylated, Distillation Residue (Distillation Residue Grade)
- Physical state: liquid
- Other: Straw coloured to dark brown liquid

Results and discussion

Applicant's summary and conclusion