AN EVALUATION OF OIL SPILL DISPERSANT TESTING REQUIREMENTS

ABSTRACT We have evaluated a number of laboratory tests of dispersant effectiveness using commercial oil spill products and No. 2 and No. 6 fuel oils. The tests-the EPA, Mackay/Steelman, Russian, French, Warren Spring, and an interfacial tension method developed at SRI-are reviewed in terms of type, scale, method of applying mixing energy, and the time required to conduct a product evaluation. The experimental results, compared in terms of the precision of the test data and the effectiveness ranking order of the six nonionic dispersants, demonstrate that the relative effectiveness found for the dispersants varies appreciably as a function of the testing method. Reasons for the variations are discussed and recommendations are presented on how to achieve dispersant testing data that are more representative of real-world conditions. Of the six testing methods evaluated, the EPA, Mackay/Steelman, and the interfacial tension methods are the most amenable to improvement.