Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The bioaccumulation potential of alkyl naphthalene was estimated usig the BCFBAF model which is part of the EPIWIN suite of models developed by the U.S. Environmental Protection Agency. The EPIWIN program calculates BCF values using both the Meylan model and the Arnot and Gobas model. These QSAR models are well established and approved by the US EPA for more than a decade. EPIWIN has been included in the OECD QSAR Toolbox.

As no definite measured log Kow is available for the substance (measurements resulted in a value >8.2, which was the upper limit of validated by the analytical method) the BCF QSAR model was used by allowing the model to calculated the Log Kow from the structure of the substance.

Alkylnaphthalene is a UVCB substance with 4 components. For a comprehensive assessment, the BCF of all 4 substances was determined.

The range of BCF estimates for the 4 components of the UVCB substance are 0.9 to 34 using the Arnot-Gobas model and 3 to 102 based on the Meylan model. The mono-alkylnaphthalene component which has the lowest concentration (2%) had the highest BCF in models (34 to 102). BCF values for the main components, tri-alkylnaphthalenes (53%) and tetra-alkylnaphthalenes (28.6%), are less than 5. The highest calculated value of 102 is proposed as a conservative estimate of the BCF.