Years ago, as a law student, I became so irked about being taxed on tampons and not chapstick that I researched the New York law. That research became the basis for a class action lawsuit filed last year challenging the state’s tampon tax, and prompted my joining a growing group of “menstrual equity” advocates. We celebrated the end of New York’s sales tax on feminine hygiene products this past fall and have set our sights on the 37 states that still burden women in sales tax overcharges by an estimated $120 million annually.

Through my work on this issue, I’ve come to believe that tampons aren’t just harming women’s finances. Commercially marketed tampons, made of toxic materials, may be seriously endangering women’s health. There are safer products now entering the market, but they cost more—and over and above the already unrealistic price of menstrual supplies of any quality for tens of millions of American women.

How serious is the problem with commercial tampon brands? Exposure to environmental toxins via tampons inserted in the vagina has never been thoroughly studied, but what we do know is alarming. The vaginal mucous membrane is not only more vulnerable to toxic chemical exposure than ordinary skin, but it’s also more vulnerable even than the mouth: Drugs are absorbed into the body over 10 times more efficiently through the vagina than when taken orally. Recently there’s been a barrage of successful lawsuits against Johnson & Johnson by women diagnosed with ovarian cancer linked to—shockingly—baby powder. Regular use on the vagina led in some cases to death.

Cancers and auto-immune disorders linked to environmental toxins have increased dramatically in the last several decades when, perhaps not coincidentally, tampon use among menstruating American women has risen to 70 percent. The average American woman will, over the course of her life, wear a tampon for the equivalent of six years, full-time.

The FDA regulates tampons, but only as Class II “medical devices.” If tampons were considered Class III (like breast implants, and arbitrarily, female condoms) tampon manufacturers would have to demonstrate the safety of their products over time. But because tampons are Class II, manufacturers only have to assert their products are safe and keep records of “adverse events,” such as the more than 200 deaths between 1979 and 1996 due to Toxic Shock Syndrome (TSS). The FDA doesn’t conduct independent tests for safety.

This means your long-term health and safety is up to you, the discerning consumer. And the FDA does not require tampon companies to disclose ingredients because tampons are considered medical devices and not cosmetics. You’re given more information about what’s in the powder on your nose than what’s in the tampon in your vagina.

So here’s the minimal, but worrying information we have: Commercially marketed tampons are made of cotton and rayon. Rayon is derived from wood pulp that in the past (i.e., only a little over a decade ago) was bleached using dioxins, now considered highly toxic and cancer-causing. In 2015 the FDA “assured” us, based on the companies’ representations (meaning the FDA didn’t require data, just promises from the companies), that dioxin levels in tampons are now “at or below” the detectable limit. This isn’t all that comforting given that the EPA now acknowledges that dioxins are highly toxic even at extremely low levels.

Conventionally grown cotton, considered the “dirtiest” of all crops due to high levels of pesticide use, could be an even bigger concern. Three independent tests since 2013 have detected pesticides listed by the EPA as “probable” carcinogens and endocrine disruptors in commercially marketed tampons. Two of those studies tested specifically for glyphosate, the key ingredient in Monsanto’s flagship weed-killing product Roundup, the most widely used pesticide in history, and a “probable” carcinogen, according to the World Health Organization—and found it in the majority of tampons tested.

Glyphosate exposure has been linked to several of the leading causes of death for American women: heart disease, cancer (breast, cervical, ovarian) and auto-immune disorders. It has been featured prominently in the news recently as the alleged cause of non-Hodgkin’s lymphoma for hundreds of farmers suing Monsanto. (Documents unsealed last month by the presiding judge suggest a collusion among Monsanto, scientists and the EPA to suppress data supporting glyphosate’s danger to human health.) Numerous independent studies have implicated glyphosate in medical conditions that are on the rise, from autism and Alzheimer’s to leaky gut and diabetes, which is why glyphosate is banned and/or restricted in many parts of the world.

Now that we’re living under a political regime hostile to both regulations and the EPA, women are more at risk than ever. What can we do?

Women’s consumer power, including in the $2.5 billion-a-year global tampon industry, may be our most powerful lever for change. For those who can afford it, that’s what should be done first: Purchase alternatives to conventional tampons, such as pads, reusables and 100 percent organic tampons—and tell everyone who can to do the same. The latter don’t use materials treated with known toxins. Additionally—and of highest importance to teenagers, who are at the greatest risk for TSS—there are no known TSS cases involving all-cotton tampons.

Second, we need to organize vociferous support for two congressional bills put forth by New York Congresswomen: Carolyn Maloney’s legislation to direct the NIH to study the risks of tampons (persistently introduced eight times over the past 20 years); and Grace Meng’s Accurate Labeling of Menstrual Products Act, which would force companies to at least list tampon ingredients.

Finally and most importantly, we need to think much bigger about how our nation can achieve “menstrual equity”—where everyone has access to the essential supplies they need to work, study, and move about the world with basic dignity. America’s 157 million women will have 450 periods in their lives, and supplies to handle their periods hygienically and safely over the long term shouldn’t just be an option for those who can afford them. This is an issue both of economic justice and public health. No woman deserves to risk her health to have her period.

Laura Strausfeld is the co-founder of Period Equity, a law and policy institute.

Co-published with Alternet.