Formic acid is widely used in pesticides, leather, textiles, printing and dyeing, pharmaceuticals, and rubber industries, among others. It can also be used to produce various solvents, plasticizers, rubber coagulants, animal feed additives, and for the synthesis of insulin using new processes. In China, the consumption of formic acid is approximately 45% in the pharmaceutical industry, 30% in the chemical industry, and 25% in other sectors such as light industry and textiles.
Formic acid is one of China's important export chemical products. Currently, all formic acid production in China uses the sodium formate method. Formic acid is commonly used as a cheap, volatile, and less corrosive substitute for inorganic acids and is widely employed in the light industry. In the textile and printing industries, formic acid is used to eliminate nitrous gas produced by the sodium nitrite method in indigosol, as a dyeing aid for weak acid dyes and neutral complex dyes, and as a dyeing assistant for reactive dyes on nylon. Formic acid does not remain on the fabric during the dyeing process, is more acidic than acetic acid, and can reduce hexavalent chromium, thereby improving dye utilization in chrome mordant processes. Using formic acid instead of sulfuric acid avoids cellulose degradation, provides moderate acidity, and ensures uniform dyeing, making it an excellent dyeing aid. As a substitute for inorganic acids, formic acid is used in tanning for decolorization, dehairing, neutralizing lime, and preventing mildew in wet leather. Using formic acid as a coagulant improves the quality of natural rubber, reduces production costs, and can also be used for the regeneration of waste rubber. Formic acid has great potential as a feed additive in silage. It can inhibit or prevent mold growth, alter the natural fermentation pattern of feed, and is often combined with fatty acids to enhance antifungal effects. Feeding dairy cows with formic acid-treated silage can prevent reduced milk production in winter and significantly improve fattening effects. In the food industry, formic acid is used for disinfection and preservation in the brewing industry, as a cleaning and disinfecting agent for canned goods, and as a preservative for juices and foods. Many derivatives of formic acid are intermediates in pharmaceuticals, pesticides, dyes, fragrances, and solvents, used in the production of borneol, aminopyrine, vitamin B1, dimethylformamide, among others. Among formic acid derivatives, substituted formamides and formate esters are more widely used in industry (for derivatives of formamide, see the respective entry).