To put in a tampon, follow the instructions on the package and wash your hands before and after use to reduce the spread of bacteria. Tampons are made of absorbent materials like cotton, rayon fibers, or a blend of both. Some tampons may also incorporate additives like glycerin or polysorbate 20. The materials used in tampons are regulated by the U.S. Food and Drug Administration (FDA) since tampons are considered medical devices. The FDA-cleared tampons are made with a bleaching process that is free from elemental chlorine, which also prevents products from having dangerous levels of dioxin. Tampons should be used for no more than 8 hours and then thrown away to reduce the risk of toxic shock syndrome (TSS) . Some states have passed laws requiring disclosure of ingredients on menstrual product packaging, but federal rules do not require it.