Formic Acid - CH₂O₂, A weak acid that photolytically reacts in the atmosphere forming COOH radical and H radical. This compound often reacts with the hydroxyl radical and atomic oxygen to form formic acid and a hydroperoxy radical. This is a sink for the hydroxyl radical and it also helps drive other reactions with the addition of hydroperoxy radicals to the atmosphere.
[Graedel and Crutzen, Atmospheric Change An Earth System Perspective. 1993. Pgs. 121,158]
Atmospheric Chemistry Glossary