Evaluation of aquatic toxicity and bioaccumulation of C8- and C9-alkylphenol ethoxylates

The extensive database of acute and chronic aquatic toxicity data for alkylphenol ethoxylates (APEs) and selected biodegradation intermediates was reviewed and summarized for freshwater and saltwater aquatic microorganisms, algae, invertebrates, and fish inhabiting cold and warm water bodies. Most acute toxicity studies that tested APE-9 and APE-10, the most common commercially relevant APEs, reported results that ranged from about 1,000 to 10,000 mu g/L. Results from studies testing alkylphenols, intermediate by-products of APE biodegradation, ranged from about 20 to 3,000 mu g/L. Chronic values are a factor of about 2 to 10 lower. Although most studies used one of several common species and standard protocols to assay conventional endpoints, many nontraditional species and toxicological endpoints were also used. This toxicological database encompasses virtually all important types of aquatic habitats and classes of aquatic species. Bioaccumulation data from both laboratory and field studies indicate that alkylphenols have a low to moderate bioaccumulation potential. Fresh weight, nonlipid-based bioconcentration factors (BCFs) measured in the laboratory ranged from <1 to 1,250 for fish and 1 to 3,400 for invertebrates, whereas field bioaccumulation factors (BAFs) ranged from 6 to 487, with most values <100. Overall, these data provide an extensive and useful database to support environmental risk assessment activities.