Clean-up efforts are under way following a weekend oil spill from a power transformer that's seeped into the East River off Brooklyn.
Coast Guard Chief Warrant Officer Allyson Conroy said Tuesday that recreational vessels are barred from a 5-mile safety zone and ferries have to move slowly.
Conroy said the insulating oil could irritate the eyes and should be washed off the skin.
Con Edison has set up booms to contain the spill. It's also been working to skim oil from the water and absorb it on the ground.
Environmental experts also were at the scene.
Con Edison said the transformer holds 37,000 gallons and "much of the oil" spilled on the ground or into the water.
The failure also caused a voltage dip that caused subway delays on Sunday.