Challenges in addressing phototoxicity and photodegradation in the environmental risk assessment of Polycyclic Aromatic Hydrocarbons in the aquatic compartment

Report no. 9/13: This report summarises how light might interact with Polycyclic Aromatic Hydrocarbons (PAHs) to alter both their environmental fate and their potential to cause adverse effects. The quantification of these changes is complicated due to the difficulties in measuring these changes in the laboratory and subsequently, in relating these to how PAHs behave in the real environment.

The consequences of attempting to account for these interactions within the framework of a generic environmental risk assessment are discussed and the conclusion reached that the impact of light on the behaviour of PAHs is best accounted for using a site-specific rather than a generic regional or generic local petroleum product risk assessment. The key elements of such an approach are described.