Dispersant Toxicities Similar, EPA Finds

A first round of toxicity tests by EPA shows that eight oil dispersants, including the Corexit 9500 that BP is applying to the Gulf of Mexico oil spill, each have about the same impact on aquatic life. Nalco’s Corexit 9500 and GlobeMark Resources’ JD-2000 are less toxic to small fish than the other products tested, EPA announced this week. JD-2000 and Saf-Ron International’s Gold dispersant are the least toxic to mysid shrimp, the agency said. The other products tested were Alabaster Corp.’s Sea Brat #4, Mar-Len Supply’s Nokomis 3-F4 and Nokomis 3-AA, U.S. Polychemical’s Dispersit SPC 1000, and Z.I. Chemicals’ ZI-400. All eight are listed on the National Contingency Plan for oil spills. Each of these products is expected to biodegrade in weeks to months, according to Paul Anastas, EPA assistant administrator for research and development. To obtain more data on the safety of dispersants, EPA is now testing each dispersant in combination with Louisiana sweet crude oil, the stuff gushing out of the Gulf of Mexico’s floor since the April 20 explosion of the Deepwater Horizon rig.