The Food and Drug Administration is warning consumers to avoid nine hand sanitizer products manufactured in Mexico because, it said, they may contain methanol, a substance that can be toxic if absorbed through the skin or ingested.
In an advisory dated Friday, the agency said it had tested samples of two products, Lavar Gel and CleanCare No Germ, and found they had 81 percent and 28 percent methanol, also known as wood alcohol.
“Methanol is not an acceptable ingredient for hand sanitizers and should not be used due to its toxic effects,” the agency said.
The F.D.A. said on June 17 that it had recommended that the manufacturer, Eskbiochem SA de CV of Mexico, remove its products from the market but that so far the company had not responded.
An Eskbiochem representative, Alexander Escamillo, said the manufacturer learned of the agency warning only on Monday.
Mr. Escamillo said another person who “had access to our company” registered it with the F.D.A. “He registered our labels and shipped sanitizers,” he said. “We did not register ourselves.”
He did not identify the person and said the company could not even log into its F.D.A. profile “because we don’t know how to.”
“We would never do that, send a toxic chemical maliciously,” Mr. Escamillo said, adding that the company would take action against the person, whom he referred to as a broker.
The F.D.A. recommended that anyone exposed to the hand sanitizers with methanol seek immediate treatment. Substantial methanol exposure can lead to nausea, vomiting, headaches, permanent blindness and seizures, among other harmful effects.
The agency said that it was unaware of any reports of “adverse events” associated with these products. It said consumers should dispose of sanitizers listed in the warning in appropriate hazardous waste containers and not flush them or pour them down the drain.
Among the other Eskbiochem products the agency flagged were CleanCare NoGerm Advanced Hand Sanitizer, with 75 or 80 percent alcohol; Saniderm Advanced Hand Sanitizer; and Good Gel Antibacterial Gel Hand Sanitizer.
It was not immediately clear when they were released for sale in the United States.
Dr. Robert Glatter, an emergency physician at Lenox Hill Hospital in Manhattan, said methanol itself was not significantly toxic. Rather, he said, it was formaldehyde and formic acid — the metabolites produced by the breakdown of methanol in the body — that could prove deadly.
Exposure to the metabolites can lead to a condition known as “metabolic acidosis, a dangerous accumulation of acid in the bloodstream, which is toxic to the organs and tissues in the body, leading to seizures, kidney failure, blindness, low blood pressure and fatal cardiac arrhythmias,” Dr. Glatter said.
Children are most at risk if they ingest methanol, but it can also be harmful if they rub it on their skin or inhale it, he added.
Sales of hand sanitizer have boomed during the coronavirus pandemic as consumers have heeded the calls of health officials to wash or sanitize their hands to keep from contracting the virus.
Historically, methanol was once manufactured by the distillation of wood. Wood alcohol was a hidden danger for unwary drinkers during Prohibition. In New York in 1926, about 750 people died after drinking wood alcohol-laced bootlegged liquor, according to an account at the Mob Museum.
Sandra E. Garcia contributed reporting.