Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Bioaccumulation

The performance of a test for bioaccumulation in aquatic species, preferably fish, is scientifically unjustified. Therefore, the bioaccumulation potential of the test item was estimated using QSAR models.

Using VEGA v1.1.4 model CAESAR v2.1.14 the BCF value of the test item was calculated to be 999 L/kg. Using T.E.S.T. v4.2.1 the BCF value of the test item was calculated to be 1275 L/kg. The substance is within the applicability domain of both model. Thus, the estimations are considered to be accurate. For risk assessment purposes as worst case scenario the value of 1275 L/kg was chosen as a key value.

Additional information

The performance of a test for bioaccumulation in aquatic species, preferably fish, is scientifically unjustified. REACH Regulation No. 1907/2006, Annex IX, Sect. 9.3.2, Col. 2, states as follows:

“9.3.2 The study need not be conducted if:

- the substance has a low potential for bioaccumulation (for instance a log Kow <= 3) and/or a low potential to cross biological membranes, or

- direct and indirect exposure of the aquatic environment is unlikely. ”

Direct and indirect exposure of the test item to water is highly unlikely. Further, the test item is practically insoluble in water. Therefore, 1,1'-(1,1,2,2-tetramethylethylene)dibenzene was considered to have no bioaccumulation potential. However, due to its low water solubility a test was omitted and a calculation of the BCF was performed and the obtained value was used for risk and PBT assessment.