Formic acid is a naturally occurring acid used as a preservative. It is typically commercially produced for industry use via chemical reaction. It may be added directly to food to prevent microorganism growth, but is also used to treat livestock feed.
Formic acid is toxic at high doses but very readily metabolized and eliminated in small concentrations. High concentrations can cause allergic reactions and have a diuretic effect.
Formic acid is rarely used due to its smell and quantity will be controlled when it is used.
Beverages, sweets, bakery products, ice cream
Sigma-Aldrich
U.S. Food and Drug Administration
Food-Info
Methanoic acid, E236