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PBT assessment

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PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB

The PBT Assessment for 2,2-dimethyl-1,3-propanediyl dioctanoate (CAS No. 31335-74-7) is based on the criteria set out in the “Guidance on information requirements and chemical safety assessment, Chapter R.11: PBT Assessment” (ECHA, 2008).


2,2-dimethyl-1,3-propanediyl dioctanoate is readily biodegradable in one study according to OECD 301 B (93.1% (CO2 evolution) after 28 d). Thus, the test substance does not meet the screening criterion for persistence and it is not considered to be P or vP.


Due to the low water solubility, rapid environmental biodegradation and metabolism via enzymatic hydrolysis of the neopentyl glycol (NPG) esters, a relevant uptake and bioaccumulation in aquatic organisms is not expected. Enzymatic breakdown will initially lead to the free fatty acid and neopentyl glycol. From literature it is well known, that these hydrolysis products will be metabolised and excreted in fish effectively (Heymann, 1980; Lech & Bend, 1980; Lech & Melancon, 1980; Murphy & Lutenske, 1990). This is supported by the low calculated BCF value 12.55 L/kg ww (BCFBAF v3.01, Arnot-Gobas, including biotransformation, upper trophic). Please refer to IUCLID Section 5.3 for a detailed overview on bioaccumulation of the NPG esters. The substance is thus not considered to be B or vB.


No effects occurred in the long-term toxicity test with Daphnia magna (OECD 211) with the read-across substance Heptanoic acid, ester with 2,2-dimethyl-1,3-propanediol (CAS No. 68855-18-5) up to the highest tested concentration 0.0019 mg/L. With Pseudokirchneriella subcapitata no effects occurred up to the limit of water solubility (NOEC >= 0.0065 mg/L). 2,2-dimethyl-1,3-propanediyl dioctanoate is not classified according to Directive 67/548/EEC and Regulation (EC) No. 1272/2008 for environmental or human health hazards. Thus, based on the current data, the criteria set out in Annex XIII of Regulation (EC) No. 1907/2006 are not met and 2,2-dimethyl-1,3-propanediyl dioctanoate does not fulfil the T criterion.