What Is Formic Acid?
Formic acid or methanoic acid is the simplest member of the carboxylic/alkanoic acid series. It occurs naturally in stinging nettle leaves and insect sings such as stingless bees, wasps, puss moth caterpillar and some ants. It can be synthetically in industries or laboratories through processes such as: hydrolyzing formamide, hydrogenation of carbon dioxide, aqueous catalytic partial oxidation of wet biomass by the OxFA process, heating oxalic acid in glycerol and extraction by steam distillation, the reaction between lead formate and hydrogen sulfide, as a by-product of acetic acid production as well as the electrochemical reduction of CO2. Formic acid is identified by the condensed chemical formula HCOOH. Pure formic acid appears as a colorless liquid with a pungent smell.
Uses of Formic Acid
Formic acid has a wide range of uses. Raspberry ants secrete formic acid from their venom gland, and then rub the secretion over its body when stung by a fire ant to protect the crazy ant from the fire ant’s venom.
Some ants sting or spray their victims with venom containing formic acid as a defensive measure when disturbed. Ants with predatory tendencies may sting or spray their prey with the formic acid venom in order to subdue them before eating them. During anting, some birds normally place ants on their feathers. The ants release venom laced formic acid that kills parasitic mites.
Besides being added to poultry feed to kill entamoeba coli bacteria, formic acid serves as a preservative and antibacterial agent in livestock feed and some human foods. When mixed with wet and high-protein fodder plants, formic acid fosters the growth of lactic acid producing bacteria and suppresses the formation of bacteria that produce butyric acid and ammonia. This promotes quick fermentation at a lower temperature and arrests certain decay processes causing the feed to retain its nutritive value for much longer.
In the industrial sector, formic acid is commonly used to create artificial flavors for foods and drinks and artificial scents for perfumes. It is also used as a coagulant in various rubber making processes, in leather tanning and dyeing and finishing textiles. The acid can be used as a fuel cell and as an intermediary to produce isobutanol from CO2. In addition, formic acid is used as a solvent in organosolvent pulping to break down lignin and hemicellulose into soluble fragments.
In most homesteads, a proper concentration of formic acid is used in various cleaning products for descaling kettles, hot water boilers, and pipe work as well as cleaning bathroom surfaces. The acid is also used as a miticide to kill varroa and tracheal mites that invade honeybee hives and attack the bees.
Stinging nettles’ stems and leaves are hairy. The hairs have a needle-like structure that is exposed when the hairs are touched. The needles of some stinging nettles sting their victims with venom that contains formic acid as a defensive measure.
Formic acid salts such as potassium formate serve as an efficient and ecologically friendly deicing agent.
Health Hazards of Formic Acid
The impact of formic acids on the health of an individual depends on its concentration. Formic acid has vapors have a repugnant smell that is irritating to the mucus membrane and may lead to nausea. Highly concentrated amounts of formic acid can lead to serious injury if it is inhaled, swallowed or touched directly. The concentrated acid is corrosive to the skin. Chronic exposure to the acid may cause kidney damage and development of a skin allergy. Swallowing the concentrated acid causes severe ulcers.