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Classification & Labelling & PBT assessment

PBT assessment

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PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB


Three extended ready biodegradation studies have been conducted with Distilled tall oil, maleated (Roulstone, 2014; Sowders, 2014a and b). Distilled tall oil, maleated was not found to meet the criteria for ready biodegradation within 28 days in any of the studies. In both the studies conducted to OECD 301D (which differed only in the concentration of inoculum used 0.08 ml per litre or 0.16 ml per litre) the 60% criteria for oxygen consumption was achieved after 60 days suggesting that Distilled tall oil, maleated would not be persistent in the environment (Sowders, 2014a and b). Biodegradation of Distilled tall oil, maleated was also observed in a further ready biodegradation study conducted to OECD 301B (52% in 42 days) (Roulstone, 2014) and in a marine biodegradation study (32.9% in 28 days) (Hamilton and Garrod, 1995). Overall, Distilled tall oil, maleated can be considered 'not persistent'.

Bioaccumulation: The available information means that Distilled tall oil, maleated cannot be ruled out as being bioaccumulative (i.e. log Kow >5.6). However, as the test substance is unlikely to persist in the environment further evidence for B or vB properties is not required.

Toxicity: The lowest EL50 value available for Distilled tall oil, maleated is 24 mg/L for algae, the EL50 for invertebrates is 56 mg/L. In a 96-hour acute toxicity test with fish no effects were observed at 10 mg/L WAF, the only test concentration. On the basis of these results distilled tall oil, maleated is not considered to be T based on the screening criteria.

There is no evidence that this class of substance is likely to be CMR and if absorbed into the body, is likely to be readily metabolised and not accumulate.

Overall the Distilled tall oil, maleated is not PBT or vPvB.