Succinic acid is a dicarboxylic acid used as a food acidity regulator. It is also a building block for bioplastics such as polybutylene succinate and a buffering agent in cosmetics and pharmaceuticals. Other uses include lacquers, perfume esters and alkyd resins. Its physical appearance is a white crystalline powder. The catalogue lists food, pharmaceutical, polymer and technical grades in 25 kg bags, 1000 kg big bags and bulk packaging. Food use as E 363 is subject to the applicable food-additive specification and permitted-use conditions. Cosmetic use is subject to the applicable cosmetic-ingredient conditions. Pharmaceutical use requires the applicable pharmacopoeia grade.