Registration Dossier

Environmental fate & pathways

Bioaccumulation: aquatic / sediment

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The bioaccumulation of DTO as a whole substance is not scientifically possible for the purpose of environmental assessment. However, for risk characterisation, it is necessary to consider the properties of the individual constituents that determine their environmental fate. As a consequence, in this section, only data describing the bioaccumulation of DTO constituents are considered.

As per ECHA communication number CCH-D-2114412576-50-01/F dated July 2018 (attached in Section 13 of the dossier), ECHA has requested the registrant to submit information on Bioaccumulation in aquatic species (Annex IX, Section 9.3.2.; test method: Bioaccumulation in fish: aqueous and dietary exposure, OECD TG 305, aqueous exposure/dietary exposure) with the block 10 constituents of the registered substance meeting P and vP criteria. The registrant is required to submit the requested information in an updated registration dossier by 18 July 2022.

Key value for chemical safety assessment

Additional information

Aquatic bioaccumulation of DTO as a whole substance

In accordance with Section 1 of REACH Annex XI, the study does not need to be conducted because the bioaccumulation of a UVCB substance of this nature should be evaluated on the basis of the properties of its constituents. A result for the whole substance is not meaningful scientifically for the purpose of assessment of exposure or risk. It is therefore not appropriate to conduct or propose a test for this endpoint. The needs associated with a sound understanding of bioaccumulation are adequately met by the available data on constituents. Reliable bioaccumulation data are characterised by quantitative structure activity relationships (QSARs) for constituents of the substance.

Aquatic bioaccumulation of DTO constituents

The basis for the Bioconcentration Factor (BCF) prediction is described in detail in the PBT assessment in Section 8 of the CSR.

There are no measured data available for bioaccumulation of individual constituents of DTO. Bioaccumulation potential was assessed for individual constituents of DTO using the appropriate QSAR from the TGD. The values for the individual constituents have been used to determine weighted averages for the blocks. The methods used to determine the BCF values are described in PFA (2010b). The resulting values for the blocks are shown in Table 4.6.

 

Table4.6: BCF values for DTO constituent blocks

Block

Constituents

Bioconcentration Factor (BCF)

1

Low boiling fatty acids

3.81E+02

2

C16 saturated - C18.3 unsaturated fatty acids

4.16E+03

3

C18 saturated - C24 saturated and unsaturated fatty acids

1.42E+04

4

Abietic acid

2.41E+02

5

Palustric acid

1.44E+03

6

Pimaric acid

2.53E+02

7

Sesquiterpene

2.86E+04

8

Abietol

-

9

Tetracosanol and dehydrated sterol

2.51E+04

10

Aldehydes

3.28E+04

11

Dimethoxystilbene

1.93E+03

12

Sitosterols and analoque

2.51E+04

13

Polymeric acids*

-

14

Polymeric neutrals*

-

*not assessed because they are high polymeric constituents