Formiasäure

Formiasäure, in English commonly called formic acid, is the simplest carboxylic acid with the formula HCOOH. Its systematic name is methanoic acid. It is a colorless, highly pungent liquid that is miscible with water and many organic solvents. It occurs naturally in small amounts in ants and nettles, where it serves as a defense chemical. Its salts are known as formates.

Formiasäure is produced on an industrial scale mainly by catalytic oxidation of methanol, often via formation of methyl formate as an intermediate, followed by hydrolysis or purification steps to yield formic acid. Alternative routes include hydrolysis of formate esters or oxidation of formaldehyde in certain processes. The compound is typically stored and handled as a concentrated solution or as the neat liquid in closed systems to minimize irritation and corrosion.

In terms of properties, formiasäure is a weak acid with a pKa around 3.75. It forms formate salts with bases and esters with alcohols (for example, methyl formate). It is used as a preservative, antimicrobial agent, and acidity regulator in the leather and textile industries, and as a chemical intermediate. It also serves as a solvent in various industrial and laboratory applications and is investigated as a hydrogen source for formic acid fuel cells.

Safety considerations include its corrosive nature and ability to cause irritation to skin, eyes, and the respiratory tract. Proper ventilation, protective equipment, and storage away from oxidizers are standard precautions.