1,1'-(1,1,2,2-tetramethylethylene)dibenzene

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

adult fish: sub(lethal) effects

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

The performance of a test for long-term toxicity to fish was considered scientifically not justified. REACH Regulation (EC) No 1907/2006, Annex VIII, Sect. 9.1.3, Col. 2, states as follows:
“9.1.3: The study (long-term toxicity to fish) does not need to be conducted if: - there are mitigating factors indicating that aquatic toxicity is unlikely to occur, for instance if the substance is highly insoluble in water or the substance is unlikely to cross biological membranes.”
or
"Long-term aquatic toxicity testing as described in Annex IX shall be considered if the chemical safety assessment according to Annex I indicates the need to investigate further effects on aquatic organisms. The choice of the appropriate test(s) will depend on the results of the chemical safety assessment."
The chemical safety assessment does not indicate the need to further investigate effects on aquatic organisms as outlined in the following. This is also in line with the rule of information requirement adaptation due to no scientific necessity as stated in Annex XI section 1.
The substance was investigated in OECD and GLP compliant studies for its acute toxicity to algae, daphnia, and fish, respectively. The test item is practically insoluble in aquatic media, therefore, supersaturated solutions of the test item were prepared for each test and the biological effects are based on loading rates. In all three trophic level tests, the test item showed no effects up to the water solubility. The E(L)C50 values were determined to be for all three species above 1000 mg/L (loading rate). The NOECs for all performed aquatic studies was determined to be ≥1000 mg/L (loading rate).
Taken together, the test item did not induce any effects in fish, daphnia and algae up to the water solubility. This is also assumed for long-term toxicity. NOEC values for a long-term fish test are expected to be well above the water solubility of the test item. Therefore, long-term toxicity studies in fish are not expected to provide more relevant information in regards to hazard conclusion and would therefore not improve chemical safety assessment.
Furthermore, based on the chemical safety assessment the environmental risk is considered to be adequately controlled. There are no concerns regarding the safe use of the substance. For the aquatic environment RCR values are beyond the threshold of 1.
Taking together the points outlined above, it is concluded that the criteria of Annex IX Section 9.1, column 2 are fulfilled justifying the adaptation of the information requirements, accordingly. Therefore, and considering animal welfare reasons, further studies on long-term toxicity to fish are neither scientifically nor from a regulatory point of view justified.
This is also in line with the rule of information requirement adaptation as stated in Annex XI section 1. Further testing does not appear to be scientifically necessary.

Description of key information

The performance of a test for long-term toxicity to fish was considered scientifically not justified.

REACH Regulation (EC) No 1907/2006, Annex VIII, Sect. 9.1.3, Col. 2, states as follows:

“9.1.3: The study (long-term toxicity to fish) does not need to be conducted if: - there are mitigating factors indicating that aquatic toxicity is unlikely to occur, for instance if the substance is highly insoluble in water or the substance is unlikely to cross biological membranes.” or "Long-term aquatic toxicity testing as described in Annex IX shall be considered if the chemical safety assessment according to Annex I indicates the need to investigate further effects on aquatic organisms. The choice of the appropriate test(s) will depend on the results of the chemical safety assessment."

The test item is practically insoluble in aquatic environment. Thus, the chemical risk assessment does not show a need for an additional long-term aquatic test. Risk assessment is based on the short-term tests for all trophic levels.

No adverse effects in long-term studies are expected and due to animal welfare, an additional study would thus not improve the environmental risk assessment.