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Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

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Description of key information

There are no reliable toxicity data for terrestrial organisms relating to 2-butyloctanol.  A waiver is applied for this endpoint as the substance is highly insoluble, readily biodegradable, has no short-term toxicity and exposure is unlikely.

Key value for chemical safety assessment

Additional information

There are no toxicity data for soil organisms relating to2-butyloctanolor other long chain alcohols.

In Annex X of Regulation (EC) No 1907/2006, it is laid down that long-term toxicity to terrestrial organisms shall be proposed by the registrant if the chemical safety assessment indicates the need to investigate further the effects of the substance and/or relevant degradation products on terrestrial organisms. Column 2 of Annex X states that studies do not need to be conducted if direct and indirect exposure of the soil compartment is unlikely.

The test substance is not supposed to be applied directly to soil. Indirect exposure to soil via sewage sludge transfer is unlikely since the substance is readily biodegradable. 

Read-across from Guerbet Alcohols and LCA categories has been used to meet the data gap for the2-butyloctanolbiodegradation endpoint, as described in the ‘Read Across Justification Document’ section 13.

A ready biodegradation study by Federle (2009) tested 10 linear primary alcohols from butanol (C4) to docosanol (C22) and concluded that all 10 LCAs are readily biodegradable and satisfy the 10-day criterion. When the biodegradation data are considered in more detail, it is clear that longer chain LCAs degrade more rapidly than the intermediate chain lengths; docosanol achieved a mineralisation level of 88% at the end of the 28-day study and 83% mineralisation within the 10-day window. Other studies by Richterich (1998a and b), Belangeret al(2009) and Federle and Itrich (2006) all reported rapid biodegradation in LCAs from C16 to C22 linear and Guerbet alcohols.

It is concluded that given the very close similarity between C6-C22 LCAs and C12 LCAs (both linear and Guerbet) as well as similar physico-chemical properties and structure, it is fully expected that the C12 LCA,2-butyloctanolwill be readily biodegradable. Indirect exposure is not expected as rapid biodegradability means2-butyloctanolwill be biodegraded within the STP process and as a consequence a transfer to the soil compartment via STP effluent is not expected.2-Butyloctanolwill not be directly applied to soils and as such, direct exposure to soil organisms is not expected. Therefore, no tests on terrestrial organisms are provided.