Guerbet alcohols, C24-26, branched and cyclic

Endpoint summary

Additional information

There are no toxicity data for terrestrial organisms relating to Guerbet alcohols, C24-26, branched and cyclic or other long chain (guerbet) alcohols ≥ C16 in length. 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. This endpoint is waived on the basis of the following arguments (i) ready biodegradability within the STP process and the environment means that direct and indirect exposure is not expected, (ii) the physico-chemical data indicate that the substance is not bioaccumulative, (iii) based on read-across from other long chain alcohols Guerbet alcohols, C24-26, branched and cyclic is unlikely to be toxic to terrestrial organisms. Unlikely Direct and Indirect Exposure Experimental data show that the substance Guerbet alcohols, C24-26, branched and cyclic is readily biodegradable. Indirect exposure is not expected as rapid biodegradability means Guerbet alcohols, C24 -26, branched and cyclic will be biodegraded within the STP process and as a consequence a transfer to the soil compartment via STP effluent is not expected. Guerbet alcohols, C24-26, branched and cyclic will not be directly applied to soils and as such, direct exposure to soil organisms is not expected. Low Bioaccumulation Potential The evidence seen in the literature (e. g. SIDS LCA Report, 2006) and in the estimated BCFs indicates that Guerbet alcohols, C24-26, branched and cyclic is unlikely to bioaccumulate in the aquatic environment. As described above, LCAs have low solubility in water making for technically challenging test conditions but they are also unavailable for uptake and bioconcentration. This was confirmed by de Wolf and Parkerton (1999) who demonstrated that long chain alcohols do not bioconcentrate because they are rapidly metabolised. On the basis of this evidence, bioaccumulation in terrestrial organisms is considered to also be unlikely and the endpoint was waived. Low Aquatic Toxicity Short-term fish studies for the structurally-related guerbet alcohols 2-octyldodecanol and C32/36 branched alcohols provide evidence of the low toxicity to fish with lethal concentrations (LC50) greater than 5, 500 to >10,000 mg/L. For invertebrates, effect concentrations in 48-hour immobilisation tests using Daphnia magna of Guerbet alcohols, C24-26, branched and cyclicr are >100 mg/L. In summary, the low solubility and ready biodegradability of Guerbet alcohols, C24-26, branched and cyclic in the environment means that it is unlikely that terrestrial life will be exposed to Guerbet alcohols, C24-26, branched and cyclic with potential to exert long-term toxic effects over extended periods. It is possible to qualitatively conclude based on low solubility and available effects data using freshwater aquatic species that Guerbet alcohols, C24-26, branched and cyclic does not pose a risk to the terrestrial compartment. In the environment, ready biodegradability means it can be assumed that Guerbet alcohols, C24-26, branched and cyclic will be biodegraded within the STP process and as a consequence a transfer to the soil compartment via STP effluent (indirect exposure) is not expected. Furthermore, for substances not passing the STP-process but being readily biodegradable, it can be assumed that they will be also biological degraded in the surface water within a short time. Guerbet alcohols, C24-26, branched and cyclic will 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.