12/23/2014 03:28 EST | Updated 02/21/2015 05:59 EST

FDA building legal case against those who sell pure caffeine powder, which can be fatal

WASHINGTON - The Food and Drug Administration is building a legal case against companies that sell pure powdered caffeine, which can be fatal even in small doses.

The FDA warned consumers to avoid pure powdered caffeine this summer after the death of an Ohio teen. Some major retailers have stopped selling it in bulk, but the substance is still widely available on the Internet and in some stores.

Even a teaspoon of the powder, which is equivalent to 25 cups of coffee, can be lethal. Eighteen-year-old Logan Stiner of LaGrange, Ohio, died in May after consuming it. It was also linked to the death of a Georgia man this year.

FDA Deputy Commissioner Michael Taylor says it is "inherently irresponsible" to market such a potentially dangerous product.