4-methylpentan-2-one

Long-term toxicity to fish

Administrative data

Endpoint:

long-term toxicity to fish, other

Type of information:

experimental study planned

Justification for type of information:

NON-CONFIDENTIAL NAME OF SUBSTANCE:
- Name of the substance on which testing is proposed to be carried out: 4-methylpentan-2-one
- Name of the substance for which the testing proposal will be used: methyl isobutyl ketone; MIBK

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 fish.
- Available non-GLP studies: There are no non-GLP studies available for this substance covering the endpoint of long-term toxicity to fish.
- (Q)SAR: QSAR approaches are currently not well fitted-for-purpose for long-term toxicity to fish 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 fully cover the endpoint of long-term toxicity to fish.
- Weight of evidence: There is no weight of evidence information available to cover the endpoint of long-term toxicity to fish.
- Grouping and read-across: There are no substances, which apply for read-across addressing long-term toxicity to fish.

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 X. Therefore, one long-term toxicity test to fish 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 study no mortalities were observed up to 179 mg/L test concentration. The LC50 was determined to be >179 mg/L (mean measured concentrations). The no observed effect concentration (NOEC) was determined to be =179 mg/L, and the LOEC was determined to be >179mg/L. Both values are based on mean concentrations.
In the short-term toxicity test to Daphnia immobilised daphnids were observed above 200 mg/L and the EC50 was calculated to be >200 mg/L. The no observed effect concentration (NOEC) was determined to be >=200 mg/L, and the LOEC was determined to be >=200 mg/L. Both values are based on nominal concentrations.
In the toxicity to aquatic algae test, a 7-day ErC50 of >146 mg/L was determined as well as a NOErC of 146 mg/L and an LOErC of >146 mg/L, after 7-day exposure using Lemna gibba.
The water solubility of the test item was determined to be ca. 14.1 mg/L at 20 °C, conducted using OECD guidelines and in compliance with GLP.


All short-term toxicity data obtained for the test substance showed effects at concentration several orders of
magnitude higher than the 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 close to the set threshold of <100 mg/L for poorly soluble substances. Based on the available information, all adaption options from Annex X are not applicable for the substance and the basic fish early life-stage study design is proposed.


FURTHER INFORMATION ON TESTING PROPOSAL IN ADDITION TO INFORMATION PROVIDED IN THE MATERIALS AND METHODS SECTION:
- The registrant intends to conduct a standard OECD 210 study based on the results of the pre-tests, which would have to be performed beforehand.
The current testing proposal will be submitted under both EU REACH and UK REACH to address 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.

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)

Test material

Test material information

Constituent 1

Reference substance name:

4-methylpentan-2-one

EC Number:

203-550-1

EC Name:

4-methylpentan-2-one

Cas Number:

108-10-1

Molecular formula:

C6H12O

IUPAC Name:

4-methylpentan-2-one

Details on test material:

No data available