Oxalic acid is an organic compound with the formula H2C2O4. It is a colorless crystalline solid that dissolves in water to give colorless solutions. It is classified as a dicarboxylic acid. In terms of acid strength, it is much stronger than acetic acid. Oxalic acid is a reducing agent and its conjugate base, known as oxalate (C2O42−), is a chelating agent for metal cations.

Typically, oxalic acid occurs as the dihydrate with the formula H2C2O4·2H2O. Ingestion of oxalic acid through skin contact or orally is dangerous.



Oxalic acid's main applications include cleaning or bleaching, especially for the removal of rust (iron complexing agent), e.g. Bar Keepers Friend is an example of a household cleaner containing oxalic acid. About 25% of produced oxalic acid is used as a mordant in dyeing processes. It is used in bleaches, especially for pulpwood. It is also used in baking powder.[4]



In humans, oxalic acid has an oral LDLo (lowest published lethal dose) of 600 mg/kg.[11]

The main toxicity of oxalic acid is due to kidney failure, which arises because it causes precipitation of solid calcium oxalate (the main component of kidney stones). Contact with oxalic acid can also cause joint pain due to the formation of similar precipitates in the joints.

Oxalic acid can also be ingested indirectly in the form of ethylene glycol. In the body, ethylene glycol is metabolised (i.e., degraded) to oxalic acid. Use of the alternative antifreeze compound propylene glycol avoids this hazard.

Forum Link1:
Forum Link2: Books

ENTER THE FORUM

Add This Forum To Your Favorites!