Oxalic acid is an odorless white solid. Sinks and mixes with water. (USCG, 1999) Oxalic acid is an alpha,omega-dicarboxylic acid that is ethane substituted by carboxyl groups at positions 1 and 2. It has a role as a human metabolite, a plant metabolite and an algal metabolite. It is a conjugate acid of an oxalate(1-) and an oxalate.

1. In the pharmaceutical industry, it is used in the manufacture of chlortetracycline, oxytetracycline, tetracycline, streptomycin, borneol, vitamin B12, phenobarbital and other drugs.

2. Used as a standard solution for calibrating potassium permanganate and cerium sulfate solutions. It serves as a bleaching agent and dye auxiliary agent, and can also be used to remove rust stains from clothes. In the construction industry, before applying exterior wall coatings, oxalic acid should be applied first to neutralize strong alkalinity on the wall surface.

3. Used as a catalyst for the synthesis of phenolic resin, with mild catalytic reaction, relatively stable process and the longest duration.