First, menstrual activists demanded that state governments remove the tax on menstrual products. Now, they want companies to list the ingredients in tampons — and for a really important reason.

The bill has the support of activists from an organization called Women’s Voices for the Earth, who rallied this week in Washington, D.C. in support of Meng’s legislation. Plus, Rep. Carolyn B Maloney (D-N.Y.) has introduced complementary legislation requesting that the National Institutes of Health conduct research into the possible harmful effects of menstrual products. So there are some big fish fighting for women’s health right now.

Said Meng in a statement,

"It is astounding that manufacturers of tampons, pads, menstrual cups and other menstrual hygiene products are not required to disclose the ingredients of these products. We can easily see the ingredients used in the shampoo we put in our hair — why doesn’t this apply to products that touch, or are inserted into, sensitive female anatomy?"

Currently, the FDA regulates menstrual products as “medical devices” — as it does condoms and dental floss, among other items — and does not require manufacturers to list ingredients on packaging. The agency suggests companies include some indication of the devices’ material composition — such as cotton, polyester, or rayon, in the case of tampons, or latex in the case of condoms — but doesn’t require further detail, as it does with shampoos and other personal-care products.

So what’s the big deal about ingredients in tampons?

First of all, activists say, women simply have a right to know what they’re putting in their bodies every single month. They also say that things like fragrances and the adhesives used in pads could be irritating or allergenic, and that’s information women need to have.

Plus, activists point out that the bleaching and manufacturing processes tampons undergo could produce harmful toxic dioxins, which have in some studies been linked to endometriosis in primates (though the FDA says that toxic dioxin levels in tampons are safe). Also, there are concerns around the use of pesticides in cotton production, since the FDA does not regulate pesticide use for medical devices as it does with food.