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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:

8. PBT AND VPVB ASSESSMENT

8.1. Assessment of PBT/vPvB Properties

8.1.1. Persistence Assessment

In a modified Sturm test DPGDB was found to have degraded by6% after 2 days, 62% after 12 days, and by 85% at the end of the 28 -day biotic phase of the test.Substances are considered to be readily degradable in this test if CO2 production is equal to or greater than 60% of the theoretical value within ten days of the level achieving 10%. In the modified Sturm test, DPGDB met these criteria, so may be considered to be readily biodegradable. Therefore, DPGDB would not be rated as persistent according to REACH Annex XIII regulation and would not be rated as a P or vP substance (half-life in fresh-water of greater than 60 days).

 

8.1.2. Bioaccumulation Assessment

A study measuring bioconcentration was not available for DPGDB. However,evidence of a low bioaccumulation potential is provided by QSAR estimates showing BCF< 200 L/kg using a regression method based upon the experimental log Kow value of 3.9, and using the Arnot-Gobas QSAR method the BCF/BAF values for all trophic levels are < 10 L/kg when biotransformation rates are utilized.For these reasons, and for animal welfare reasons, it is believed that a bioconcentration study is not justified and is not proposed.The QSAR values support a low potential to bioaccumulate and are well below the REACH Annex XIII criteria for B or vB.

8.1.3. Toxicity Assessment

All three trophic levels were represented in aquatic toxicity studies: primary producers represented by algae, plant eating invertebrate animals represented by daphnids, and freshwater fish. LC/EC50 values for all of these organisms were > 1 mg/L. DPGDB is not classified as carcinogenic (category 1 or 2), mutagenic (category 1 or 2) or toxic for reproduction (category 1, 2 or 3). There is no evidence to suggest that DPGDB would be classified as T/R48 or XN/R48 for chronic toxicity. Therefore DPGDB does not meet the T criterion.

 

8.1.4. Summary and overall conclusions on PBT or vPvB properties

DPGDB is readily biodegradable and therefore is not P or vP. QSAR data suggests a low potential for DPGDB to bioaccumulate. However, as an experimental BCF study is not available for DPGDB the lack of B or vB criterion is not definitive. Aquatic toxicity is minimal and it is not rated as a mutagen or toxic for reproduction and available studies do not support DPGDB as having adverse chronic toxicity or being a carcinogen, therefore the T criterion is no met. Based upon the fact that substances are classified when they fulfil the criteria for all three inherent properties for P, B and T, DPGDB cannot be classified as a PBT or vPvB as it is not Persistent (P) or Toxic (T) based upon experimental data, In addition, QSAR data suggests that DPGDB is not B or vB as well.