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Ecotoxicological information

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
experimental study planned
Justification for type of information:
TESTING PROPOSAL ON VERTEBRATE ANIMALS

NON-CONFIDENTIAL NAME OF SUBSTANCE:
- Name of the substance on which testing is proposed to be carried out: 1,6-hexanediyl-bis(2-(2-(1-ethylpentyl)-3-oxazolidinyl)ethyl)carbamate

CONSIDERATIONS THAT THE GENERAL ADAPTATION POSSIBILITIES OF ANNEX XI OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION:
- Available GLP studies: There are no GLP studies available for this substance covering the endpoint of long-term toxicity to aquatic invertebrates.
- Available non-GLP studies: There are no non-GLP studies available for this substance covering the endpoint of long-term toxicity to aquatic invertebrates.
- (Q)SAR: QSAR approaches are currently not well fitted-for-purpose for long-term toxicity to Daphnia and consequently no firm recommendations can be made concerning their routine use in a testing strategy in this area (ECHA Guidance on Information Requirements and Chemical Safety Assessment Chapter R 7a: Endpoint specific guidance, 2017).
- In vitro methods: There are no in vitro methods available to cover the endpoint of long-term toxicity to aquatic invertebrates.
- Weight of evidence: There is no weight of evidence information available to cover the endpoint of long-term toxicity to aquatic invertebrates.
- Grouping and read-across: : There are no substances which apply for read-across addressing long-term toxicity to aquatic invertebrates.

CONSIDERATIONS THAT THE SPECIFIC ADAPTATION POSSIBILITIES OF ANNEXES VI TO X (AND COLUMN 2 THEREOF) OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION:
The substance is fully registered according to REACH Annex VIII. Therefore, one long-term toxicity test to aquatic invertebrates study is legally required. The test substance has been tested in a series of short-term aquatic tests. In the key short-term toxicity to fish test no mortalities were observed up to 100 mg/L test concentration. The LC50 was determined to be 199.2 mg/L (nominal concentration). In the short-term toxicity test to Daphnia immobilised daphnids were observed above 125 mg/L and the EC50 was calculated to be 193 mg/L, in the same range as the effects observed in the short-term toxicity to fish study. In the toxicity to aquatic algae test, an EC50 of 43 mg/L was determined as well as a NOEC of 12.5 mg/L after 72 h exposure. The experimental determination of the water solubility of the test item was technically not feasible as the test item decomposes immediately when in contact with water and solid precipitate of the hydrolysis products is formed, thus, the experimental determination was substituted with a QSAR estimation. The water solubility was calculated to be ca. 1.7 mg/L at 25 °C. All short-term toxicity data obtained for the test substance showed affects at concentration several orders of magnitute higher than the estimated water solubility. Based on this information, it is considered that the test item is not toxic up to its water solubility. Based on the phys-chem properties of the test item, it can be assumed that it falls in the category of "difficult to test substances" as the water solubility was estimated to be close to the set threshold of 1 mg/L for poorly soluable substances. Based on the available information, all adaption options from Annex IX are not applicable for the substance and the basic Daphnia reproduction study design is proposed.

FURTHER INFORMATION ON TESTING PROPOSAL IN ADDITION TO INFORMATION PROVIDED IN THE MATERIALS AND METHODS SECTION:
The registrant indends to conduct a standard OECD 211 study based on the results of the pre-tests, which would have to be performed beforehand.
The current testing proposal will be submitted both under EU REACH and UK REACH to adress the data gap in the study requirements.
The registrant requests the Authority to take into account that CROs are currently fully booked with regard to long-term fish tests and that a pre-test incl. method development would need to be performed, when setting the deadline for submission of the test results.

Data source

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 211 (Daphnia magna Reproduction Test)

Test material

Constituent 1
Chemical structure
Reference substance name:
(E)-N-{6-[(E)-({2-[2-(heptan-3-yl)-1,3-oxazolidin-3-yl]ethoxy}(hydroxy)methylidene)amino]hexyl}{2-[2-(heptan-3-yl)-1,3-oxazolidin-3-yl]ethoxy}carboximidic acid
EC Number:
925-259-5
Cas Number:
140921-24-0
Molecular formula:
C32H62N4O6
IUPAC Name:
(E)-N-{6-[(E)-({2-[2-(heptan-3-yl)-1,3-oxazolidin-3-yl]ethoxy}(hydroxy)methylidene)amino]hexyl}{2-[2-(heptan-3-yl)-1,3-oxazolidin-3-yl]ethoxy}carboximidic acid

Results and discussion

Applicant's summary and conclusion

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