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Classification & Labelling & PBT assessment

PBT assessment

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PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB
Justification:

Straightforward assessment of PBT and vPvB properties was not possible for the substance. Among the substance properties the fate and physical-chemical properties of hydrocarbon blocks identified from the substance were taken into account in the assessment as far as possible. In order to take into account the uncertainty related to the assessment, appropriate RMM and OC are proposed for the substance in ES&RC.

Rationale:

Assessment of PBT and vPvB properties of the substance was difficult because of the substance properties. The substance is a UVCB substance containing constituents with different kinds of physical-chemical properties. Therefore, there were many difficulties related to the assessment:

-application of PBT and vPvB criteria was not straightforward

-testing of BCF was not technically feasible for the substance

-there were uncertainties related to the testing of Kow properties and biodegradation

-acute aquatic toxicity was tested with WAF and effective exposure determined as loading rates

Due to these difficulties, there are uncertainties related to the assessment. All available data on the substance was taken into consideration in the assessment (instead of applying only specific criteria defined in REACH Annex XIII).

Conclusions on P not vP:

Based on the available data, the substance might be determined as persistent (P) or very persistent (vP). According to ready biodegradability screening test, the substance was not readily biodegradable. It should be noted that interpretation of test results is not straightforward due to the substance properties. The half-life estimated for hydrolytically stable substance is over one year. Based on the half-life, the substance would be very persistent (vP). According to the biodegradation potential of the hydrocarbons in the substance, this substance contains both biodegradable and non-biodegradable constituents. These results also show potential for persistence properties. Based on the available data, this substance is proposed to be considered as persistent (P).

Conclusions on not B or vB:

As determination of BCF experimentally was not feasible, the bioaccumulation potential of the substance was assessed based on test results from 1) the experimental octanol-water partitioning coefficient study (log Kow of 6), 2) estimated log Kow values (PETRORISK), and 3) estimated BCF and BAF values (EPISUITE). Based on the experimental log Kow data, the substance might contain substances having potential for bioaccumulation. For complex mixtures (e.g. UVCBs) a single value of Kow will not be definitive. The log Kow values were also estimated with the PETRORISK tool that was used for the environmental risk assessment. The estimation is based on log Kow values of individual compound structures, which are included in the CONCAWE Library. The overall range for the estimated log Kow values was from 2.55 to 13.23. The log Kow values of the representative individual structures that form the major part of the substance based on mass fraction (sum 0.64) were in the range 5.25 - 9.82. The range of log Kow values indicated that there might be constituents present in the substance having potential for bioaccumulation (log Kow > 4.5). However, constituents with very high log Kow values (> 6) are expected to have reduced bioaccumulation potential.

Bioconcentration factors and bioaccumulation factors were also estimated with the BCFBAF v3.01 model. The estimated log BCF value for the ten most abundant individual structures of the substance ranged from 1.98 to 3.18 (BCF 95 to 1513 L/kg). The estimated log BAF value for the ten most abundant individual structures of the substance ranged from 4.19 to 5.28. In conclusion, as the estimated BCF values are less than B or vB criteria (2000 and 5000 L/kg) this substance is not B or vB.

Conclusions on T:

Based on the aquatic toxicity test results of the substance and the results of toxicological studies with surrogate material, this substance is not fulfilling the criteria as toxic (T).

Likely routes of exposure:

Straightforward assessment of PBT and vPvB properties was not possible for the substance. Based on the assessment this substance is considered as P but not fulfilling the criteria for B, vB or T. In order to take into account the uncertainty in the assessment, appropriate RMM and OC are presented in the CSR Sections 9 and 10.