Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Substance is not bioaccumulative on the basis of available data.

Additional information

The substance is a hydrocarbon UVCB. Assessment using the US EPA On-Line EPI Suite™ KOWWIN version 1.68 model, the log Kow range is predicted to be 7.49 to 31.33.As the substanceshows log Kow values in the main of > 10,it is proposed that the substance is not indicative of being potentially bioaccumulative, on the basis of the partition coefficient values observed.

The substance is, however, considered to be not bioavailable to aqueous organisms as demonstrated by the lack of toxicity. Furthermore, the high log Kow is considered to be more a consequence of poor water solubility than a lipophilic tendency and is considered to be not indicative of the tendency to bioaccumulate in lipid tissues of aquatic organisms. This is based in part on an evaluation of literature data which demonstrates a tendency for the Bioconcentration Factor (BCF) to decrease as Log Pow increases above 6. This assumption is further confirmed by the data set available on the substance which demonstrates that it is poorly absorbed, both on the basis of the toxicity (or lack of) observed, plus the absorption study which demonstrated the lack significant absorption in the rat.

The above opinion is also confirmed via use of the EPIWIN BCFBAF v3.01 for assessment of bioaccumulation. The smallest and largest theoretical molecular weight substances were assessed and the following results were demonstrated:

Smallest: BCF 1944 L/kg wet-wt

Largest: BCF 3.162 L/kg wet-wt

 

All evaluated values are less that <2000, indicating that the substance is not proposed to be bioaccumulative.

 

Evaluation of predicted molecular size data indicates that approximately 29% of the molecules are of a Dmax average of greater than 17 Å (1.7 nm) plus a molecular weight of greater than 700 (Da). 

 

Taking into account the following:

 

·        Lack of absorption

·        Lack of persistency

·        High predicted log Kow value.

·        Low predicted bioaccumulation potential

·        Molecular size data not being indicative of the propensity towards bioaccumulation.

  

This indicates, within a weight of evidence approach and with expert judgment, that NovaSpec Renewable White Oil is deemed to not be bioaccumulative in aquatic organisms.