. It would not be accidental. Estimated adult lethal dose is 5 to 10 grams of fluoride
. Topical Fluoride strength is 1.23% by volume (0.0123). You would therefore have to ingest 400 to 800 grams of the gel, all at once (14 to 28 ounces). The teaspoon or so you put in your mouth during application will not harm you.