Toxicity testing shows that a mixture of Corexit 9500 and Number 2 fuel oil is more than four times as toxic as Number 2 fuel oil alone and nearly ten times more toxic than Corexit alone Additionally, comparison of toxicity testing results for dispersants listed on the Product Schedule show that Corexit 9500, when mixed with Number 2 fuel oil, is the dispersant that is most toxic to silversides (an estuary fish tested under required protocols) and the second least effective at dispersing South Louisiana crude oil.

NRDA TWG group taking samples from oiled marsh in Louisiana

Oil sheen surfacing near plugged Macondo well

Herring samples taken in 2010 as part of a three year study to determine why the herring population never recovered from the post-Exxon Valdez collapse