Benzene, 1,4-bis(1-methylethyl)-, homopolymer

Endpoint summary

Additional information

Discussion

The acute aquatic toxicity of the test item was investigated for fish, Daphnia and algae. The test item was not water soluble and therefore tested as suspension. No signs of toxicity were observed. The test item is considered to be not acute toxic for the aquatic system.

Short- term toxicity to fish

The acute toxicity of the test item to fish was investigated in a static system using Brachidanio rerio (Danio rerio (EEC/92/69, C.1)). No mortality was observed after the exposure period of 96 hours. The LC50 was estimated to be > 100 mg/L and NOEC was determined to be 100 mg/L. The test item is considered to be not toxic to fish.

Long-term toxicity to fish

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”

The test item is practically insoluble in aquatic environment. In addition, based on the high Log Pow of 9.2, the substance is very unlikely to pass biological membranes. The substance is not toxic to all 3 trophic levels in acute tests. Therefore, the substance is not expected to be toxic in chronic tests. Thus, the CSR 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.

Short- term toxicity to aquatic invertebrates

Acute toxicity of the test item was investigated in a static test using Daphnia magna as model system (EEC/92/69, C.2). The test item was insoluble in water. No toxicity was observed for 100 mg/L nominal concentration after exposure period of 48 hours. The EC50 was estimated to be > 100 mg/L. The NOEC was determined to be 100 mg/L. The test item is considered to be not toxic to aquatic invertebrates.

Long-term toxicity to aquatic invertebrates

REACH Regulation (EC) No 1907/2006, Annex IX, Sect. 9.1, Col. 2, states as follows:

“9.1.: Long-term toxicity testing shall be proposed by the registrant if the chemical safety assessment according to Annex I indicates the need to investigate further the effects on aquatic organisms. The choice of the appropriate tests(s) depends on the results of the chemical safety assessment."

A study assessing the long-term toxicity of the test item CCPIB towards aquatic invertebrates (Daphnia sp.) according to OECD 211 guideline is currently not available. The studies assessing the short-term toxicity of the test item towards fish, aquatic invertebrates (Daphnia sp.) and algae clearly show no adverse effects up to the test item's water solubility. In addition, based on the high Log Pow of 9.2, the substance is very unlikely to pass biological membranes. The substance is not toxic to all 3 trophic levels in acute tests Therefore, the substance is not expected to be toxic in chronic tests.

Short- term toxicity to algae and cyanobacteria

The test item was investigated for its acute toxicity in a static test system using Selenastrum capricornutum (EU- Method, C.3). The test item was not water soluble. After the 72 hour exposure no signs of toxicity were observed. The EC50 was estimated to be > 300 mg/L and NOEC was determined to be 100 mg/L. The test item is considered to be not toxic for algae.

Toxicity to microorganisms

The test item was investigated for its toxicity to microorganisms following OECD209. The test item did not inhibit respiration of activated slugde within the exposure period of 3 hours. The EC50 was estimated to be > 300 mg/L and NOEC / EC10 was determined to be 300 mg/L. The test item is considered to be not toxic to microorganisms.