Polysorbate 80 is a nonionic surfactant and emulsifier often used in foods and cosmetics. Polysorbate 80 is an excipient that is used to stabilize aqueous formulations of medications for parenteral administration, and used as an emulsifier in the manufacture of the popular antiarrhythmic amiodarone. Polysorbate 80 is also used as an excipient in some European and Canadian influenza vaccines. Influenza vaccines contain 25 μg of polysorbate 80 per dose. Polysorbate 80 is also used in the culture of Mycobacterium tuberculosis in Middlebrook 7H9 broth. It is also used as an emulsifier in the estrogen-regulating drug Estrasorb. In Europe and America, people eat about 100 mg of polysorbate 80 in foods per day on average. Polysorbate 80 has not been found to be carcinogenic. Rats fed with diets containing up to 5% polysorbate 80 by volume for 12 weeks showed no toxic effects.