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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:

The PBT Assessment for Reaction mass of bis(2-propylheptyl) hexanedioate and O6-[2,2-bis[[6-oxo-6-(2-propylheptoxy)hexanoyl]oxymethyl]butyl] O1-(2-propylheptyl) hexanedioate is based on the criteria set out in the “Guidance on information requirements and chemical safety assessment, Chapter R.11: PBT Assessment” (ECHA, 2012).

Persistence

The test substance is readily biodegradable in one study according to OECD 301B (60 - 70% (CO2 evolution) after 28 d). Thus, the test substance does not meet the screening criterion for persistency and it is not considered to be P or vP.

 

Bioaccumulation

Reaction mass of bis(2-propylheptyl) hexanedioate and O6-[2,2-bis[[6-oxo-6-(2-propylheptoxy)hexanoyl]oxymethyl]butyl] O1-(2-propylheptyl) hexanedioate is not expected to be bioaccumulative. Due to their readily biodegradable nature, extensive degradation of the substance in conventional STPs will take place and only low concentrations are expected to be released into the environment. Once present in the aquatic compartment, further biodegradation will occur. Based on high log Pow, low water solubility and high adsorption potential, the main components Bis(2-propylheptyl) hexanedioate and O6-[2,2-bis[ [6-oxo- 6-(2-propyl heptoxy)hexanoyl]oxymethyl]butyl] O1-(2-propylheptyl) hexanedioate might be bioavailable to aquatic organisms such as fish only by oral uptake adsorbed on suspended organic particles. After uptake in fish, extensive and fast biotransformation of the main constituents by carboxylesterases into adipic acid, trimethylolpropane and via 2-propylheptanol to 2-propylheptanoic acid is to be expected. The alcohol is used by these organisms as their main source of energy throughout all the different life stages (early development, growth, reproduction, etc.). Adipic acid does not have the potential to accumulate in adipose tissue due to their low log Pow. The key study with the suitable read across substance reports a BCF value of 27, which clearly indicate that rapid metabolism takes place even when log Pow values are above the trigger value of 4.5. Supporting BCF/BAF values estimated using BCFBAF v3.01 confirm the experimental result for the main constituents and the degradation products of the test substance (all well below 2000). The information above provides strong evidence supporting the statement that rapid metabolism and low bioaccumulation potential can be expected for the main constituents and the expected metabolites of the test substance.

 

Toxicity

Experimental data for the test substance investigating the toxicity to algae and of the main constituent DPHA investigating the long-term toxicity to fish and invertebrates are available. No effects on survival and reproduction up to the solubility of the substance in water were observed for all trophic levels. The available data indicate that long-term toxicity to aquatic organisms in the range of its water solubility is not to be expected. Moreover, the test substance is not classified according to Directive 67/548/EEC and Regulation (EC) No. 1272/2008. Thus, the criteria set out in Annex XIII of Regulation (EC) No. 1907/2006 are not met and the test substance is not considered to meet the T criterion.

 

Conclusion

In conclusion, Reaction mass of bis(2-propylheptyl) hexanedioate and O6-[2,2-bis[[6-oxo-6-(2-propylheptoxy)hexanoyl]oxymethyl]butyl] O1-(2-propylheptyl) hexanedioate is not considered to meet the criteria to be classified as PBT or vPvB based on the available data.