tert-butyl peroxypivalate

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species: fish

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

REACH Regulation No. 1907/2006, Annex IX, Sect. 9.3.2, Col. 2, states: “9.3.2: The study need not to be conducted if the substance has a low potential for bioaccumulation (for instance a log Kow ≤ 3) and/or a low potential to cross biological membranes, or direct and indirect exposure of the aquatic compartment is unlikely.”

Direct and indirect exposure of substances of the peroxyester group to surface water is highly unlikely.

Substances of the group of peroxyesters have been found to be non-persistent (please refer to IUCLID Section 5.3.1). The test item itself was demonstrated to be readily biodegradable.

Very low exposure of the water compartment is further 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 OECD 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 peroxides.

In addition, the bioaccumulation potential has been estimated by QSAR calculation. The test item was within the applicability domain of the model and thus fulfilling validity criteria of the QSAR calculation. The obtained calculated BCF value is below the threshold value of 2000 L/kg and thus not fulfilling the B criterion.

This further indicates that there is no concern as regard to the bioaccumulating potential of the test item.

In conclusion, according to REACH Annex IX, Sect. 9.3.2, Col. 2 a bioaccumulation study does not need to be conducted since exposure to the aquatic environment is unlikely, as outlined above. With respect to the PBT or vPvB assessment a bioaccumulation test is also not indicated since the test item is readily biodegradable and thus, not persistent (neither P nor vP). In addition, QSAR calculation indicates no concern regarding bioaccumulation.

Furthermore, vertebrate studies shall only be the conducted as a last resort. Thus, a BCF study in fish is also not justified considering animal welfare reasons.

Description of key information

A study does not need to be conducted according to REACH Annex IX Section 9.3.2. Column 2.