Propylparaben
Propylparaben, the n-propyl ester of p-hydroxybenzoic acid, occurs as a natural substance found in many plants and some insects, although it is manufactured synthetically for use in cosmetics, pharmaceuticals, and foods. It is a member of the class of parabens. It is a preservative typically found in many water-based cosmetics, such as creams, lotions, shampoos, and bath products. As a food additive, it has the E number, which is E216. Sodium propyl p-hydroxybenzoate, the sodium salt of propylparaben, a compound with formula Na(C3H7(C6H4COO)O), is also used similarly as a food additive and as an anti-fungal preservation agent. Its E number is E217. In 2010, the European Union Scientific Committee on Consumer Safety stated that it considered the use of butylparaben and propylparaben as preservatives in finished cosmetic products as safe to the consumer, as long as the sum of their concentrations does not exceed 0.19%. Uses 
Propylparaben has antifungal and antimicrobial properties and is typically used in a variety of water-based cosmetics and personal-care products. It is also used as a food additive, and is designated with E number, E216. Propylparaben is commonly used as a preservative in packaged baked goods, particularly pastries and tortillas. Propylparaben is also a Standardized Chemical Allergen and is used in allergenic testing. As of May 2023, New York began considering banning the use of propylparaben because studies in humans and animals indicate that it acts as an endocrine disrupter and affects male and female reproductive health. In September of 2023, California passed legislation outlawing the use of propylparaben in foods by 2027. The new law bans the manufacture, sale and distribution of propylparaben and three other additives. This is the first law in the U.S. to ban it and will possibly have nationwide effects. References 

Parabens
Propyl esters

ja:プロピルパラベン