Fatty acids, C16-18 and C18-unsatd., reaction products with glycidyl neodecanoate and 7-oxabicyclo[4.1.0]hept-3-ylmethyl 7-oxabicyclo[4.1.0]heptane-3-carboxylate

PBT assessment

PBT assessment: overall result

Reference

Name:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Type of composition:

legal entity composition of the substance

State / form:

liquid

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

Reference substance:

Esterification reaction of fatty acids, C16-18 and C18-unsatd.; 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexan carboxylate and neodecanoic acid, oxiranylmethyl ester

PBT status:

the substance is not PBT / vPvB

Justification:

Persistence: The results from the ready biodegradability CO₂ evolution test indicated 48% biodegradation in 28 days; therefore, under test conditions, ready biodegradability was not observed. The degradation rate of 48% in 28 days is evidence of inherent, primary biodegradability (> 20% biodegradation; ECHA, Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.7b: Endpoint-specific guidance, Version 3.0, February 2016, Section R.7.9.4.1, p. 209) and significant mineralisation (> 40% degradation; ECHA,Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.7b: Endpoint-specific guidance, Version 3.0, February 2016, Section R.7.9.5.4, p. 237). The ready biodegradability test is a screening criterion; therefore, no definitive determination on persistence can be made based on available information. However, in the absence of a definitive determination, the substance may be described as “potentially persistent” (“potentially P”), based on its degradation rate falling below the threshold criterion for ready biodegradability.  In addition, the substance is described as “not very persistent” (“not vP”), based on its inherent biodegradability and significant mineralisation in the ready biodegradability test.  The substance is a UVCB which contains substantial proportions of sunflower oil fatty acids, derivatized with a diepoxide (Diepoxide 126) to form various esters. The base materials of these substances are naturally-occurring lipids, suggesting that environmental biodegradation is expected, even if a degradation rate meeting the strict criteria for ready biodegradability has not been observed.

 

Bioaccumulation: A precise value for the octanol-water partitioning coefficient of the substance could not be experimentally determined, but was reported as log Kow > 6.2. This value is above the threshold for the screening criterion (i.e., log Kow ≤ 4.5), at or below which a substance may be considered as both “not bioaccumulative” (“not B”) and “not very bioaccumulative” (“not vB”). Since the predicted value of partition coefficient exceeds this screening threshold, the substance may be considered “potentially bioaccumulative” (“potentially B”).

 

However, additional evidence indicates that the substance is unlikely to be very bioaccumulative. Based on QSAR modeling, the predicted octanol-water partition coefficient for a major constituent of the substance (molecular weight 813.22) was log Kow = 16.5226 (EPI-Suite v4.11, KOWWIN v 1.68). This predicted value for log Kow is greater than 10; ECHA guidance states that the “aquatic BCF of a substance is probably lower than 2000 if the calculated Log Kow is higher than 10” (ECHA,Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.11: PBT/vPvB assessment, Version 2.0, November 2014, Section R.11.4.1.2, p. 55).

 

The UVCB contains substantial proportions of sunflower oil fatty acids derivatized with Diepoxide 126 to form various esters. Approximately 91% of the substance, by weight, is comprised of reaction products with molecular weights greater than 700 g/mol. A substance molecular weight greater than 700 g/mol “is an indicator that the BCF is below 5000” and thus below the threshold for very bioaccumulative (ECHA,Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.11: PBT/vPvB assessment, Version 2.0, November 2014, Section R.11.4.1.2, p. 54). Approximately 9% of the reaction mass is comprised of residual single sunflower oil fatty acids and epoxides, with molecular weights below 700 g/mol. The preponderance of substance components with a molecular weight greater than 700 g/mol (i.e., more than 90% by weight of the UVCB) is an indicator that the substance is not likely to be very bioaccumulative.

 

Toxicity:A definitive determination regarding the mammalian toxicity of the substance indicates that the substance is not toxic. With respect to mammalian toxicity, the substance has not been classified as “carcinogenic, mutagenic or toxic for reproductive toxicant” (CMR) and has not been classified as “STOT RE” with respect to chronic exposures; these are definitive determinations of “not T” with respect to mammalian toxicity.

 

The results of the short-term aquatic toxicity tests indicate that that the substance is “presumably not toxic” (“presumably not T”) when compared to the screening criteria for short-term aquatic toxicity.  The EC50 values for algal growth inhibition, short-term daphnid toxicity and short-term fish toxicity of the substance were each reported at > 100 mg/L. In addition, the NOEC from the algal growth inhibition study was reported at 32 mg/L for both the growth rate and yield endpoints, indicating that chronic toxicity is several orders of magnitude above the definitive criterion (NOEC < 0.01 mg/L) for toxicity. Since both inherent biodegradability and significant mineralisation were observed in a ready biodegradability test, the substance may be considered as “presumably not T" for both acute and chronic exposures. The substance is "not T" with respect to mammalian toxicity, based on definitive criteria (the substance has not been classified as “carcinogenic, mutagenic or toxic for reproductive toxicant” (CMR) and has not been classified as “STOT RE” with respect to chronic exposures). The substance is "not T" with respect to aquatic toxicity, based on the screening criterion (the lowest L(E)C50 for all three trophic levels is ≥ 0.01 mg/L). 

 

Conclusions: Any determination based on screening criteria requires that “each of the three properties persistency, bioaccumulation and toxicity need to be considered in conjunction” (Chapter R.11, “PBT Assessment”,Guidance on information requirements and chemical safety assessment, ECHA, May 2008, Section R.11.1.2.2, p. 13). Therefore, the substance is considered as “not PBT “(potentially P, potentially B and presumably not T) and “not vPvB” (not vP, not vB).