The government warned consumers on Friday to avoid using toothpaste made in China because it may contain a poisonous chemical used in antifreeze.

According to the Associated Press, the FDA said that people should throw away toothpaste with labeling that it was made in China. The FDA worries that these products could contain diethylene glycol.

The agency is not aware of any reports in the United States of poisoning from toothpaste, but it did find the antifreeze ingredient in a shipment at the US border and at two retail stores: a Dollar Plus store in Florida and a Todo A Peso store in Puerto Rico, a US territory.

Officials said they are concerned primarily about toothpaste sold at bargain retail outlets. The ingredient in question, called DEG, is used as a low-cost sweetener and thickening agent. The highest concentration of the chemical found in toothpaste so far was between 3% and 4%, but the FDA’s Deborah M. Autor said, “It does not belong in toothpaste even in small concentrations.”

The FDA increased its scrutiny of toothpaste made in China because of reports of contamination in several countries, including Panama. The agency is particularly concerned about chronic exposure to DEG in children and in people with kidney or liver disease. Agency officials said they had no estimate of how many tubes of tainted toothpaste might have made it into the United States.

“Our concern today is potentially about all toothpaste that comes in from China,” Autor said. “Our estimate is that China makes up about $3.3 million of the $2 billion US toothpaste market.”

The agency also issued an import alert for all dental products containing DEG. The alert means that toothpaste from China will be stopped at the border, she said.

The alert says the agency found DEG in three products manufactured by Goldcredit International Trading in China. The products are Cooldent Fluoride, Cooldent Spearmint, and Cooldent ICE. The agency also found the chemical in one product manufactured by Suzhou City Jinmao Daily Chemical Co in China. Analysis of that product, Shir Fresh Mint Fluoride Paste, found that it contained about 1% DEG.