The Food and Drug Administration announced that the U.S. distributor of Nuclear Sludge chew bars is recalling the candy because of lead contamination. No one has been sickened, but the FDA said elevated lead content could be harmful to small children, infants and pregnant women.

The candies were manufactured in Pakistan. Indianapolis-based Candy Dynamics said it would stop selling all Nuclear Sludge candy in the U.S. The candy is wrapped in bright yellow caution-like tape, and the company’s website features the screech of a blaring warning horn. The bars were distributed in stores throughout the U.S. and Canada.

“Our product’s tongue-in-cheek brand name in no way reflects the vigilant approach the company takes toward product integrity,” the company said in a statement.

The California Department of Public Health first detected the contamination, measuring the candy’s lead content at 0.31 parts per million. FDA regulations require foods to be below 0.1 parts per million.

Nuclear Sludge launched in 2007 and was not a major seller for the company, with sales of $32,000 last year.

“Nuclear Sludge did have a fan base, but our other products have been more popular,” said Laura King, Candy Dynamic’s Vice President.

Candy Dynamics also sells sour lozenges, which come in a miniature “Toxic Waste” drum oozing green sludge, and chewing gum, under the brands Short Circuit and Hi-Voltage.

The company said a review of those products found no evidence of lead contamination.

Candy Dynamics’ website links to Youtube.com videos showing children grimacing as they sample the company’s products.

In recent years, U.S. regulators have struggled to assure the safety of a wave of food imports from countries like Pakistan, China and India. In 2008, the FDA opened its first inspection offices in China after contaminated pet food, toothpaste and other products reached U.S. stores.