Testing has helped confirm that chemicals used to disperse oil from the BP spill have not made their way into fish, crabs, shrimp or oysters from the Gulf of Mexico, U.S. officials said on Friday.

Tests of more than 1,700 samples show that fewer than 1% had any trace of chemicals at all, and the ones that did had extremely low levels, the officials from the Food and Drug Administration and the National Oceanic and Atmospheric Administration said.

"This additional round of testing has confirmed ... that Gulf seafood brought to market is safe," Dr. Vicki Seyfert-Margolis, FDA's senior adviser for science and innovation, told a telephone briefing.

The Deepwater Horizon oil drilling rig exploded in April, killing 11 workers and spilling about 4.9 million barrels or 185 million gallons of crude oil.
Earlier on Friday the Institute of Medicine committee released a report recommending better research on oil spills and the dispersant chemicals used to clean them up.

"The committee recommends that priority be given to obtaining information that is as comprehensive as possible about exposure to the oil, dispersants, and by-products of the controlled burns," the panel of experts wrote in their report.

The institute, an independent organization that advises the federal government on health matters, also recommended that the Health and Human Services Department research a way to "deploy a rapid research response for future oil spills and other potential disasters."

Dr. John Stein, director of NOAA's seafood safety program, said the chemical test is a back-up for so-called sensory testing in which trained experts sniff seafood for evidence of chemical contamination.

The chemical test looks for dioctyl sodium sulfosuccinate, or DOSS, one of the main compounds in the dispersants used to break up the spilled oil.

"DOSS is also approved by FDA for use in various household products and over-the-counter medications at very low levels," the agencies said.

"The results confirm the results of our sensory testing. Absolutely none of the samples pose a threat to human health," Stein said.

A White House panel said on Thursday that Halliburton used flawed cement in the doomed Gulf well, which could have contributed to the blowout.