O,O'-dioctadecylpentaerythritol bis(phosphite)

Endpoint summary

Additional information

Aquatic bioaccumulation

This substance is predicted to have a high Kow value (16.4); a value in excess of 4.5 is considered to indicate a potential for bioaccumulation, according to screening criteria for bioaccumulation in ECHA guidance (Chapter R.11 PBT Assessment). The likely reliability of the log Kow is, however, considered to diminish above a value of 6, as noted in Appendix R.11-1 Annex 1 of ECHA guidance on PBT Assessment. Substances with log Kow between 4.5 and 6 are considered likely to be highly accumulating; however no substantial bioconcentration is assumed for compounds having log Kow values greater than 6. For compounds having log Kow greater than 6, a gradual decrease of the BCF is observed and it has been hypothesised within the published literature that a high log Kow is more an effect of solubility than a tendency of the substance to be lipophilic. Based on QSAR modelling, the BCF value for the test substance is estimated to be 3.162 L/kg ww indicating that it has a low potential for bioaccumulation.

Furthermore, WESTON 618 is hydrolytically unstable, and will hydrolyse to form 1-octadecanol, pentaerythritol and phosphoric acid.

The fate of 1-octadecanol (stearyl alcohol) is well documented. It is insoluble in water and of low toxicity, and is metabolised to triglycerides, phospholipids and cholesterol esters. The fate of pentaerythritol is also well documented, as it is a metabolite of the drug pentaerythritol tetranitrate. In humans, pentaerythritol is readily excreted unchanged (see Toxicokinetics Assessment attached to IUCLID Chapter 13).

Terrestrial bioaccumulation

As stated above, WESTON 618 is likely to be readily hydrolysed to form 1-octadecanol, pentaerythritol and phosphoric acid therefore it is expected to have a low potential to bioaccumulate.