Overview of Aquatic Toxicity Testing under the U.S. EPA Oil Research Program

Abstract

2017-063 ABSTRACT The U.S. EPA Office of Research and Development is developing baseline data on the ecotoxicity of selected petroleum products, chemical dispersants, and other spill mitigating substances as part of its Oil Research Program. Two diluted bitumens (dilbits) from the Alberta Tar Sands region are being tested for acute and chronic toxicity to standard freshwater and marine organisms given their spill potential during shipment within the United States. Separately, crude oils representing a range of characteristics and representative dispersants are being tested to evaluate acute and chronic toxicity to marine organisms in support of proposed regulatory amendments to Subpart J of the U.S. National Contingency Plan. Water accommodated fractions (WAF) of oil are prepared using traditional slow-stir methods and toxicity tests follow U.S. EPA standard effluent testing guidelines, modified for testing petroleum products. WAFs are characterized for petroleum hydrocarbons including alkyl PAH homologs. Future research plans include evaluating oil spill mitigating substances such as surface washing and bioremediation agents. The results of the research program will assist the U.S. EPA in assessing toxicity of unconventional oils (dilbits), and establish baseline toxicity data for selected crude oils and spill mitigating substances in support of planning and response activities.