The US Food and Drug Administration has expanded its list of potentially deadly hand sanitizer products, warning a Mexican-based company about selling products that contain methanol, a dangerous form of alcohol that can poison people through their skin. "A warning letter has been issued to Eskbiochem S.A. de C.V. for distributing product with undeclared methanol, unapproved claims --including incorrectly stating FDA approval—and improper manufacturing practices," the agency added.