NOAA, the FDA and the Gulf states have been rigorously testing Gulf seafood for oil—doing smell tests with teams of human sniffers, and performing chemical tests for the harmful polycyclic aromatic hydrocarbons, or PAHs, found naturally in crude oil.

But they’re not chemically testing—at least, not yet—for the presence of oil dispersant. BP has thus far applied more than 1.7 million gallons of one chemical dispersant, Corexit, to the Gulf. (The lack of dispersant testing for seafood has been mentioned by The Palm Beach Post and CNN, but we first noticed toward the end of this Los Angeles Times piece.)

Both the FDA and the National Oceanic and Atmospheric Administration say that dispersant in seafood isn’t the primary concern—it’s oil, because the oil is more likely to be found in the flesh of the fish. Teams of scientists--whose noses are believed to be sensitive enough to sniff out oil--are also trained to detect the smell of dispersant, but the chemical testing is limited to crude oil hydrocarbons.

“There is, however, work being done here to develop testing for dispersant. That’s ongoing,” said Monica Allen, a spokeswoman with the National Marine Fisheries Service, a division of NOAA.

Until that dispersant test is ready, both the FDA and NOAA have said that “based on current science,” the dispersants BP is using have “a low potential to bioaccumulate in fish flesh and are low in human toxicity, and therefore there is no significant public health risk associated with consuming seafood that has been exposed to them.”

But the current science on dispersants is pretty thin, as some federal agencies have acknowledged.

“There’s not a huge body of research that has been done,” Meghan Scott, an FDA spokeswoman, told me. “While we are finding that [dispersant] is harmful to the living fish itself, there’s a difference between what it does to a living fish and any harm that it might have for a human consuming a fish that was in or near water with dispersant in it.”

NOAA said it is working on tests to better understand dispersants’ bioaccumulation.

The manufacturer of Corexit, Nalco, has maintained that ingredients in its product “do not bioaccumulate and are commonly found in popular household products.”

The dearth of dispersant research has also led the EPA to do independent testing of dispersant toxicity, separate from the manufacturers’ toxicity data. A first round of testing found that all eight dispersants tested were roughly equal in toxicity when tested alone, and did not significantly disrupt the hormones of small fish and shrimp. Further testing is being performed to determine how toxic the combination of oil and dispersant is.

All that said, there’s no need for hysteria, but it’s good to be aware of unanswered questions and possible gaps in the current testing.