Registration Dossier

Ecotoxicological information

Sediment toxicity

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Administrative data

Endpoint:
sediment toxicity
Type of information:
experimental study planned
Study period:
This study is to be conducted dependent upon the results of the proposed soil simulation study (OECD 307) in dossier point 5.2.3. If necessary, the study will be commenced within six months of completion of the soil simulation study.

Data source

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: OECD 233: Sediment-Water Chironomid Life-Cycle Toxicity Test Using Spiked Water or Spiked Sediment, 2010
Principles of method if other than guideline:
First instar chironomid larvae are exposed to a concentration range of the test substance in a sediment-water system. The test starts by placing first instar larvae (1st generation) into test beakers containing spiked sediment or alternatively the test substance is spiked into the water after addition of the larvae. Chironomid emergence, time to emergence and sex ratio of the fully emerged and alive midges are assessed. Emerged adults are transferred to breeding cages, to facilitate swarming, mating and oviposition. The number of egg ropes produced and their fertility are assessed. From these egg ropes, first instar larvae of the 2nd generation are obtained. These larvae are placed into freshly prepared test beakers (spiking procedure as for the 1st generation) to determine the viability of the 2nd generation through an assessment of their emergence, time to emergence and the sex ratio of the fully emerged and alive midges (a schematic presentation of the life-cycle test is provided in Annex 5). All data are analysed either by a regression model to estimate the concentration that would cause X% reduction in the relevant endpoint, or by using hypothesis testing to determine a No Observed Effect Concentration (NOEC). The latter requires a comparison of treatment responses with the appropriate control responses using statistical tests. It should be noted that in the spiked water scenario, in case of fast degrading substances, the later life stages of each generation (e.g. pupal phase) might be exposed to a considerably lower concentration level in the overlying water than the 1st instar larvae. If this is a concern, and a comparable exposure level for each life stage is needed, the following amendments of the test method might be considered:

- parallel runs with spiking at different life stages, or
- repeated spiking (or overlying water renewal) of the test system during both test phases (1st and 2nd generation), whereby the spiking (renewal) intervals should be adjusted to the fate characteristics of the test substance.

Such amendments are only feasible in the spiked water scenario, but not in the sediment spiked scenario.
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test organisms

Test organisms (species):
Chironomus sp.

Results and discussion

Applicant's summary and conclusion