Tert-butyl hydrogen phthalate is an organic chemical that is used in the production of polyvinyl chloride, butyral, and polypropylene. It is also used as a plasticizer for polyvinyl acetate and polystyrene. Tert-butyl hydrogen phthalate is an anti-aging agent for vinyl, which increases its resistance to oxidation. This chemical has been shown to be effective as a stabilizer for polyvinyl chloride against degradation by dichromate, stearic acid, and peroxide. Tert-butyl hydrogen phthalate reacts with succinic acid to form tert-butyl succinate and hydrogen chloride.