PT13 Aquatic Ecotoxicology I
Exhibit Hall
8:00 AM - Tuesday
(PT180) Ecotoxicological assessment of nonylphenol ethoxylate surfactants.
Staples, C1, Mihaich, E2, Carbone, J3, Klecka, G4, Losey, B5, 1 Assessment Technologies, Inc., Fredericksburg, VA, USA2 E. M. Mihaich Consulting, Durham, NC, USA3 Rohm and Haas Company, Spring House, PA, USA4 The Dow Chemical Company, Midland, MI, USA5 APE Research Council, Beechwood, NJ, USA
ABSTRACT- Nonylphenol ethoxylate (NPE) surfactants are widely used commercial products. Primary uses include industrial and institutional cleaners, production of pulp and paper, textiles, and as emulsifying agents, dispersants and adjuvants. Most uses involve the release of spent surfactant into wastewater treatment systems. After biological degradation and removal, trace levels of the parent surfactants and their biodegradation intermediates can be detected in effluents from wastewater treatment plants. Thus, aquatic wildlife may be exposed to the surfactants. Commercial products such as NPE-4 and NPE-9 are actually mixtures of numerous oligomers ranging from NPE-1 to NPE-20 or higher, but averaging either 4 or 9 ethoxylate units. Therefore, aquatic toxicity tests are needed on the commercial mixtures for an ecotoxicological assessment. While considerable data are available on the lower ethoxylates (NPE-1,2) and nonylphenol, few data on the commercial mixtures are available. This research program consists of a series of chronic tests with fish, invertebrates and algae with NPE-4 or NPE-9 surfactants. These results and other available data were used in an ecotoxicological assessment of the full range of nonylphenol ethoxylate surfactants.
Key words: NPE-4, aquatic toxicity, NPE-9, biodegradation intermediates