D-Glucitol, 1,5-anhydro-1-C-[3-[[5-(4-fluorophenyl)-2-thienyl]methyl]-4-methylphenyl]-, 2,3,4,6-tetrakis(2,2-dimethylpropanoate), (1S)-

PBT assessment

PBT assessment: overall result

Reference

Name:

T003422

Type of composition:

legal entity composition of the substance

State / form:

solid: particulate/powder

Related composition:

T003422

Reference substance:

T003422

PBT status:

the substance is not PBT / vPvB

Justification:

An evaluation of the inherent properties of T003422 is performed against the ANNEX XIII criteria. If insufficient data were available, the screening criteria as laid down in ECHA Guidance on information requirements and chemical safety assessment Chapter R.11: PBT Assessment (2014) were applied.

 

The persistency assessment is based on the screening criteria in Annex XIII of the REACH Regulation. The biodegradation potential of the test substance has been assessed in an OECD 301B study (Desmares-Koopmans, 2016). The substance is considered not readily biodegradable, as no significant biodegradation was observed (1% under the conditions of the test). Hence the substance could be classified as preliminary persistent according to the screening criteria. A hydrolysis study shows abiotic degradation of the substance. Half-lives obtained for T003422 are much lower than the P (and vP) criterion of t1/2> 40 (or 60) days. Due to a combination of hydrolysis and photolysis of this substance, observed DT50 values at 20°C were 1.9, 6.7 and 2.9 days at pH 4, 7, and 9 respectively. These data suggest that in the aquatic environment T003422 will hydrolyse/photolyse rapidly at all environmentally relevant pH levels. Nonetheless, abiotic degradation data such as hydrolysis and photolysis half-life values cannot be compared directly to the REACH Annex XIII persistence criteria. Based on the data above, T003422 is currently treated as if it meets the P/vP criteria.   

 

The bioaccumulation assessment is based on the screening criteria in Annex XIII of the REACH Regulation. The BCF for the test substance was estimated using the regression-based method implemented within the BCF/BAF v3.01 of EPI-Suite. Using the experimental Log Kow of >7.0, the modeled BCF value of 1.06 x 10⁴ was very high, yet considered unreliable due to the nature of the experimental Log Kow value (i.e., expressed as "greater than" due to the limitations of the used methodology). Using the Log Kow value of 11.46 as estimated using the KOWWIN model, the resulting BCF value was only 87.1 (i.e., greatly below the cutoff criterion to consider a substance as bioaccumulative). This value suggests that the test substance should not be considered bioaccumulative. Since the Log Kow value estimated using KOWWIN is more realistic than the experimental value, and T003422 was also found to fall within the applicability domain of KOWWIN, the BCF value of 87.1 is considered more realistic as well. As such, T003422 is considered not bioaccumulative, based on its predicted BCF being much lower than the B assessment criterion of 2000.  

 

In addition, based on the structure of the parent molecule, predictions of the structures of the breakdown products/metabolites were made using the QSAR model/expert system EAWAG-BBD Pathway Prediction System. The prediction showed that the 2,2 -dimethylpropanoic acid (CAS 75-98-9) parts split off from the parent compound leading to a remaining part (Cc1ccc(cc1Cc1ccc(s1)-c1ccc(F)cc1)[C@@H]1O[C@@H](C(O)C(O)C1O)C([O-])=O) of which the predicted BCF value was 3.16 L/kg (BCFBAF v3.01). The aerobic likelihood of the prediction was “very likely”. Based on this information, the hydrolysis product Cc1ccc(cc1Cc1ccc(s1)-c1ccc(F)cc1)[C@@H]1O[C@@H](C(O)C(O)C1O)C([O-])=O is not expected to show significant bioaccumulation. 

 

The available evidence on the toxicity potential for the substance is sufficient for an assessment based on the Annex XIII criteria for this endpoint. Chronic toxicity data is available the three trophic levels (fish, aquatic invertebrates, and algae). The 32d-NOEC for fish was determined to be 3.9 µg/L, which is below the cutoff value of 0.01 mg/L for the T properties based on the Annex XIII criteria of REACH.

 

To conclude, based on the available information T003422 is considered not a PBT/vPvB substance.