Citric acid
Citric acid is an organic compound with the chemical formula HOC(CO2H)(CH2CO2H)2.[10] It is a colorless weak organic acid.[10] It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in the metabolism of all aerobic organisms.[10]
"E330" redirects here. For the locomotive, see FS Class E330.
More than two million tons of citric acid are manufactured every year. It is used widely as an acidifier, as a flavoring, and a chelating agent.[11]
A citrate is a derivative of citric acid; that is, the salts, esters, and the polyatomic anion found in solutions and salts of citric acid. An example of the former, a salt is trisodium citrate; an ester is triethyl citrate. When citrate trianion is part of a salt, the formula of the citrate trianion is written as C
6H
5O3−
7 or C
3H
5O(COO)3−
3.
Safety[edit]
Although a weak acid, exposure to pure citric acid can cause adverse effects. Inhalation may cause cough, shortness of breath, or sore throat. Over-ingestion may cause abdominal pain and sore throat. Exposure of concentrated solutions to skin and eyes can cause redness and pain.[51] Long-term or repeated consumption may cause erosion of tooth enamel.[51][52][53]