tert-butyl 2-ethylperoxyhexanoate

Sediment toxicity

Link to relevant study record(s)

Reference

Endpoint:

sediment toxicity: long-term

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 toxicity to sediment organisms is considered not scientifically justified.
REACH Regulation No 1907/2006, Annex X, Sect. 9.5.1, Col. 2, states as follows: “9.5.1: Long-term toxicity testing shall be proposed by the registrant if the results of the chemical safety assessment indicates the need to investigate further the effects of the substance and/or relevant degradation products on sediment organisms. The choice of the appropriate test(s) depends on the results of the chemical safety assessment.”

The chemical safety assessment does not indicate the need to further investigate the effects on sediment organisms for the following reasons:

Direct and indirect exposure of the peroxyesters to the sediment is highly unlikely.

Substances of the peroxyester group are not stable in the aquatic environment. Due to the unstable nature of organic peroxides, it can be assumed that upon contact with water and organic matter, the substances undergo degradation resulting in the formation of respective alcohols and acids. Therefore, an abiotic degradation of the test item in the environment is expected. In addition, the test item was found to be readily biodegradable.

The test item is further not expected to have a potential for bioaccumulation (calculated BCF<< 2000 L/kg). Please also refer to IUCLID section 5.1.3.

Consequently, long-term toxicity testing is considered scientifically not justified since the test item is not stable in the aquatic environment and long-term exposure to sediment organisms is not expected.

Further, Environmental Risk Assessment reveals safe use of the substance throughout its whole life cycle due to very low exposure of the water compartment which is especially based on the following facts:

Organic peroxides, when released into the sewage of a manufacturing or a downstream user plant, are treated with other substances in dedicated sewage treatment plants. The activated sludge from these sewage treatment plants is then removed and treated as chemical waste. From the production plant, the release of organic peroxide into the sewage is very limited, not to say negligible. The waste water from production plant can be treated on site (at least a physical/chemical treatment, which will decompose organic peroxides by chemical reaction), which is usually followed by a biological treatment. Regarding industrial end-uses, organic peroxides are mainly used as cross-linking agent/polymerization initiator for the production of resins/rubbers/polymers. Based upon the fact that organic peroxides are totally consumed during the process (>99%, which is confirmed by the release factor to sewage for curing agents from ESD n°3), the surface water is not exposed to organic peroxides via the waste water system. As a consequence, the surface water is not considered to be significantly exposed by the organic peroxide.

Thus, the environmental Risk Assessment does not indicate a need for a long-term toxicity study on sediment organisms. Risk assessment is based on aquatic toxicity studies.
Thus, a study is considered not scientifically justified according to REACH Regulation No. 1907/2006, Annex X, Sect. 9.5.1., Col. 2.

Description of key information

A study does not need to be conducted according to REACH Annex X Section 9.5.1, Column 2.