Fatty acids, C16 and C18-20 (even numbered, unsaturated), 2-ethylhexyl esters

Endpoint summary

Link to relevant study record(s)

Reference

Endpoint:

basic toxicokinetics

Type of information:

other: Theoreitcal assessment

Adequacy of study:

weight of evidence

Objective of study:

toxicokinetics

Qualifier:

no guideline followed

Principles of method if other than guideline:

Theoretical assessmnet of toxicokinetic properties

GLP compliance:

no

Conclusions:

Conclusion

Based on the common metabolism and enzymatic description, it is considered justifiable to apply results from the epoxidised oil ETP to Fatty acids, C12-20 and C12-20-unsatd., 2-ethylhexyl esters for the derivation of critical endpoints.

The read across justification for a non toxic epoxidised natural ester and an unsaturated natural ester is proposed through the low toxicity of a central epoxidised unsaturated ester compared to a central unsaturated alkene.

The toxicity profile of the 2-ethyl hexyl ester structural component which is identical for both the EDT epoxy and the Fatty acids, C12-20 and C12-20-unsatd., 2-ethylhexyl esters was demonstrated as having low toxicity from the EDT data.

Description of key information

The EODs are considered a category for purposes of environmental and health hazard screening assessments because of the similarities in metabolism (uptake results in rapid metabolism by esterases) of these materials in microbial, aquatic and mammalian systems. Carboxylesterases have been demonstrated to be present in many families of fish and aquatic invertebrates as well as mammals.The action of the esterase will result in a mixture of epoxidized fatty acids and 2-ethylhexanol fromETP. The similarity of the epoxidized fatty acids which are the primary constituents of the metabolic products of the EOD materials make it possible to use the data of representative materials within this category to assess the potential hazards across the category. In mammalian species these materials are expected to be absorbed and metabolized in a similar fashion, resulting in the release of similar free epoxidized fatty acids and lesser substituted alcohols or glycerides.

 

Similarly, it could be expected that the action of the esterase would result in a mixture of naturally occurring fatty acids and 2-ethylhexanol from Fatty acids, C12-20 and C12-20-unsatd., 2-ethylhexyl esters. 

 

Toxicokinetics are expected to be similar since Fatty acids, C12-20 and C12-20-unsatd., 2-ethylhexyl estersis a mixture of saturated and unsaturated monoesters of 2-ethylhexanol and ETP is an epoxidised monoester of 2-ethylhexanol. Routes of uptake and metabolism are similar in mammalian systems and the metabolic products via carboxylesterase activity are also similar.

 

The OECD SIDS review confirmed the similarities in metabolic breakdown and fate of the epoxidised oils group. Based on similar structures and similar metabolic pathways, it can be assumed that human health responses are likely to be similar for ESBO, ELO, ETP and, therefore also forFatty acids, C12-20 and C12-20-unsatd., 2-ethylhexyl esters(as similar structure to ETP)

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

50

Absorption rate - dermal (%):

50

Absorption rate - inhalation (%):

100

Additional information

In the absence of substance-specific data, default assumptions are made regarding the extent of absorption.