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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

The PBT Assessment for Fatty acids, C16-18 and C18-unsatd., dimerized, “Crude dimer” (CAS No. 71808-39-4) is based on the criteria set out in the “Guidance on information requirements and chemical safety assessment, Chapter R.11: PBT Assessment” (ECHA, 2012).


Fatty acids, C16-18 and C18-unsatd., dimerized, “Crude dimer” showed not to be readily biodegradable in one OECD 301 ready biodegradation study (29.3% after 28 d). Due to the low solubility and high adsorption potential, it might be the case that the test substance is persistent especially in soil.Thus, as possible worst case, the persistence of the test substance in the environment is assumed.


The screening criterion for Bioaccumulation (B) stipulated in the ‘Guidance on information requirements and chemical safety assessment – Chapter R.11: PBT Assessment’ (ECHA, 2008) is a Log Kow > 4. Even though Log Kow values > 4 were estimated for the category members, no significant bioaccumulation in animal tissue is expected due their low potential to cross biological membranes and their metabolic fate in organisms. Thus, the category members can neither be considered to be bioaccumulative (B) nor very bioaccumulative (vB).


Long-term toxicity testing with Danio rerio resulted in no effects up to the water solubility limit for a read-across substance (ISO/DIS 10229-1).Moreover, the test substance is not classified according to Directive 67/548/EEC and Regulation (EC) No. 1272/2008 (2nd ATP).Thus, the criteria set out in Annex XIII of Regulation (EC) No. 1907/2006 are not met and the test substance is not considered to meet the T criterion.