2-Octen-1-ylsuccinic anhydride, mixture of cis and trans

PBT assessment

PBT assessment: overall result

Reference

Reference 1

Name:

dihydro-3-(octenyl)furan-2,5-dione

Type of composition:

boundary composition of the substance

State / form:

liquid

>= 99 - <= 100 % (w/w)

Reference substance:

dihydro-3-(octenyl)furan-2,5-dione

Reference substance:

dihydro-3-(octenyl)furan-2,5-dione

Reference substance:

dihydro-3-(octenyl)furan-2,5-dione

This impurity is considered relevant for the classification and labelling of the substance

Reference 2

Name:

dihydro-3-(octenyl)furan-2,5-dione

Type of composition:

legal entity composition of the substance

State / form:

liquid

>= 99 - <= 100 % (w/w)

Reference substance:

dihydro-3-(octenyl)furan-2,5-dione

Reference substance:

dihydro-3-(octenyl)furan-2,5-dione

Reference substance:

dihydro-3-(octenyl)furan-2,5-dione

This impurity is considered relevant for the classification and labelling of the substance

PBT status:

the substance is not PBT / vPvB

Justification:

Persistence: The results from the ready biodegradability test (screening criterion) indicated 71.66% biodegradation in 19 days, thus exhibiting ready biodegradability of the substance. The hydrolysis test (additional consideration) indicated rapid hydrolysis at environmentally relevant pH conditions and temperatures (i.e.,at pH 7, DT₅₀= 8.3 minutes at 15^oC and DT₅₀= 4 minutes at 25^oC). Each of these hydrolysis half-life values is substantially below the threshold half-life of 24 hours which provides “clear evidence of environmental degradation” (Chapter R.7.b, “Endpoint-specific guidance”, Guidance on information requirements and chemical safety assessment, ECHA, May 2008, Section R.7.9.5.3, p. 193). Hydrolysis is the most significant abiotic degradation process, as it “may proceed effectively in aquatic, sediment and soil compartments” (Chapter R.11, “PBT Assessment”, version 1.1,Guidance on information requirements and chemical safety assessment, ECHA, November 2012, Section R.11.1.3.1, p. 19). This information demonstrates that the substance is “not persistent” (“not P”) and “not very persistent” (“not vP”) in the environment. 

 

Bioaccumulation: The octanol-water partitioning coefficient for the substance (log K_ow≥4.68) indicates that the value does not meet the screening criterion (i.e., log K_ow≤4.5) to determine that the substance is “not bioaccumulative” (“not B”) and “not very bioaccumulative” (“not vB”); this estimation of the partition coefficient was based upon the ratio of solubilities inn-octanol and water. However, the substance has been shown to undergo rapid hydrolysis at environmentally relevant pH and temperature conditions  (i.e.,at pH 7, DT₅₀= 8.3 minutes at 15^oC and DT₅₀= 4 minutes at 25^oC). Each of these hydrolysis half-life values is substantially below the threshold half-life of 12 hours, below which “it can be assumed that the rate of hydrolysis is greater than that for uptake by exposed organisms” (Chapter R.7.c, “Endpoint-specific guidance”,Guidance on information requirements and chemical safety assessment, ECHA, May 2008, Section R.7.10.3.4, p. 24). The guidance then states that “in most cases hydrolysis products are more hydrophilic and as a consequence will have a lower potential for bioaccumulation” (Ibid.). This statement is consistent with the predicted partition coefficient for octenyl succinic acid, the hydrolysis product of the substance (log K_ow= 3.42), which falls substantially below the screening criterion for “not B” and “not vB” (i.e., log K_ow≤4.5). Therefore, based on a weight of evidence regarding the rapid hydrolysis of the substance and the predicted partitioning behaviour of the hydrolysis product, the substance may be determined to be “not B” and “not vB”.

 

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”, T, 48” or “Xn, R48” 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” (“not T”) when compared to the screening criteria for short-term aquatic toxicity.  The LC₅₀for fish (based on read-across from tetrapropenyl succinic anhydride, another substance in the category) was reported at > 100 mg/L, the EC₅₀ for daphnids (based on read-across from tripropenyl succinic anhydride, another substance in the category) was reported as > 100 mg/L, and the E_rC₅₀ for algae (based on read-across from tetrapropenyl succinic anhydride, another substance in the category) was reported as 110 mg/L (based on cell count). Therefore, all acute toxicity L(E)C₅₀values were four orders of magnitude above the definitive aquatic toxicity criterion of L(E)C₅₀< 0.01 mg/L, and three orders of magnitude above the aquatic toxicity screening criterion of L(E)C₅₀< 0.1 mg/L. Since the substance does not exhibit the potential for bioaccumulation and has been shown to undergo rapid hydrolysis in the environment, the substance may be considered to be presumably "not T" for both acute and chronic exposures. 

 

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 to be “not PBT “ (not P, not B and presumably not T) and “not vPvB” (not vP, not vB).