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Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

The registration item and its relevant transformation products do not have a significant potential for bioaccumulation.

Additional information

The substance is an UVCB substance. In accordance with Annex IX, Section 9.3.2 and Section the assessment of bioaccumulation or bioconcentration and biodegradation of each constituent and impurity present in concentrations at or above 0.1% (w/w) must be performed. Experimental testing of the potential for bioaccumulation of the registration item itself is not technically possible due to the complex UVCB nature of the substance and the large number of constituents. Therefore, QSAR approaches have been applied to investigate the degradation behaviour of the registration item.
Since the substance is a reaction product with ethoxylated and propoxylated components, there is no unique molecular structure of the registration item existing. Therefore, three representative chemical structures (large, medium and small) covering the molecular size range and structural differences of the UVCB were selected. Results obtained for these three substructures are considered representative of the entire UVCB substance and therefore allow for the assessment of the registration item:

Constituent 1 (CC(O)CNc1ccc(C)cc1NCCO), small size

Constituent 2 (CC(CN(CCOCC(C)O)c1ccc(C)cc1N(CCOCC(C)O)CCOCC(C)OCC(C)O)OCC(C)O), medium size

Constituent 3 (CC(CN(CCOCC(C)OCC(C)O)c1ccc(C)cc1N(CCOCC(C)OCC(C)O)CC(C)OCC(C)OCC(C)O)OCC(C)OCC(C)O), large size

These structures do not exist separately and cannot be synthesized or isolated with justifiable effort. Due to the lack of the experimental data for the constituents, the assessment of their potential to bioaccumulate has been performed via several QSAR estimations.
Calculated solubilites in octanol of the three substructures range from 2.8 to 12.3 g/L (see chapter 4.9) and are therefore well below the "unlimited" solubility of oTDA-EO-PO in water. Although this ratio provides limited evidence, it is nevertheless a hint towards a low potential for bioaccumulation of the registration item. In addition, the test substance has a log Kow < 3 (0.42 -2.3 for representative structures of the UVCB, see chapter 4.7) which indicates a low potential for bioaccumultation.
Furthermore, one QSAR model of CATALOGIC, one QSAR model of the EpiSuite (BCFBAF) and three QSAR models of VEGA have been used. The criteria listed in Annex XI of Regulation (EC) No 1907/2006 are considered to be adequately fulfilled and therefore the endpoint(s) sufficiently covered and suitable for risk assessment.

Considering all models applied constituents of the registration item are estimated to have BCF values range between 0.06 and 186 L/kg.