Clean-up crews and locals in the Gulf Coast have something new to worry about, and it isn’t just the small sea of crude oil frothing ashore. Now, workers and residents are also facing the early consequences of oil giant BP’s decision to litter the waters with two dispersant chemicals from a line called Corexit.

Both chemicals, according to The Huffington Post, are banned in the U.K. for their toxicity.

The Environmental Protection Agency (EPA) has warned BP against using Corexit, on the grounds that it is more toxic and less effective than other available clean-up alternatives.

Indeed, Corexit 9500, one of the chemicals used in the Coast, is as toxic as crude oil at only one-fifth of its volume, though it is present in lesser quantity than the oil itself. Regardless, Corexit chemicals are now present in the coast’s ecosystem, and are beginning to affect life there.

BP’s intention in using dispersant chemicals was, supposedly, to break up the spilled oil into microscopic droplets.

In theory, these droplets can then diffuse throughout the ocean to be slowly digested by bacteria over time, reducing their harm to the fragile ecosystem.

While Americans wait for the dispersant chemicals to do their job, however, the oil and chemicals are mixing with coastal waters, creating a hazard to human, avian, and marine life.

“We have no idea how the dispersants will affect the wildlife in the Gulf Coast. We’ve never used that much before in that large of an area,” said Associate Professor of Biology Dr. Melanie Lee-Brown.

Gulf Coast resident, commercial fisherman, and Vietnam War veteran Donny Matsler told Al Jazeera of his symptoms after having come into contact with contaminated waters.

“I started to vomit brown, and my pee was brown also,” said Matsler. “I kept that up all day. Then I had a night of sweating and non-stop diarrhea unlike anything I’ve ever experienced.”

Corexit, which was also used in response to the Exxon Valdez disaster of 1989, was believed in post-spill medical studies to have been linked with human health problems including respiratory, nervous system, liver, kidney, and blood disorders, according to journalistic source ProPublica.

“There’s going to be a legacy of contamination in the gulf food web,” said Gina Solomon, a senior scientist for the Natural Resources Defense Council in correspondence with The Washington Post.

In response to complaints that cleanup workers were showing signs of respiratory illnesses, including nasal irritation, nausea, and sore throat, then-BP CEO Tony Hayward offered his suggestion that said workers were simply suffering the symptoms of food poisoning.

“I’m sure they were genuinely ill,” Hayward stated. “But (it’s unclear) whether it had anything to do with dispersants and oil, whether it was food poisoining, or some other reason for being ill.”

Despite the recent health complaints, BP has officially stated that they still will not offer clean-up workers gas masks.