Diglycolic acid is an aliphatic dicarboxylic acid, its acidity is between the one of acetic acid and oxalic acid. It is formed in the oxidation of diethylene glycol in the body and can lead to severe complications with fatal outcome.
The compounds of every Wikipedia article carrying a Chembox or a Drugbox, refreshed daily, with the values their infoboxes give. The pages need JavaScript; the API does not.