On any given day, millions of American women are menstruating – and more than half of them are using tampons. What many of those women don’t know is that there is no research that unequivocally declares these feminine hygiene products safe, and independent studies by women’s health organizations have found chemicals of concern like dioxin, carcinogens and reproductive toxins present in tampons and pads.

The multi-billion dollar feminine hygiene industry likes to say that the amounts of those toxins in a single tampon is very low. But the average woman who uses tampons will use over 16,800 during the course of her lifetime – and there is almost no data on the health effects of the cumulative use of tampons over a woman’s lifetime.

Imagine if we only examined the health effects of smoking a single cigarette.

Many women throughout America (and throughout the world) are concerned about the health and environmental effects of the feminine hygiene products they use every day. But limited information and incomplete data means that we don’t know precisely which unhealthy chemicals and contaminants could be present or what the effects of long-term, monthly tampon use could be.

Not only is our data not cumulative, it’s also far from comprehensive. Currently, the FDA requires tampon manufacturers to monitor dioxin. But dioxins are only one of many toxins that should be monitored, and there are many other products – like the douches, sprays, wipes and cups used by millions of women – that are not examined at all.

That all needs to change.

Recently, I introduced the Robin Danielson Feminine Hygiene Product Safety Act of 2015, which directs the National Institutes of Health (NIH) to research whether feminine hygiene products pose health risks and it encourages the Food and Drug Administration (FDA) to broaden its monitoring efforts and publicly disclose a list of contaminants within the wide range of feminine hygiene products available on the market. The legislation is named for Robin Danielson, a woman who died tragically in 1998 at the age of 44 from Toxic Shock Syndrome, which is linked to high-absorbency tampon use – but it’s a disease we still don’t understand particularly well, and the CDC stopped monitoring its prevalence in the United States.

This lack of data on cumulative tampon use, feminine hygiene product toxicity and the chemicals present in all such products is not at all surprising. Women’s health has been perennially under-represented and overlooked when it comes to clinical research and studies. Until the 1980s, women were largely left out of medical research – which meant that almost no health data was collected on women – and most medical trials only included male subjects. Even when scientists studied diseases that largely impacted women (such as breast cancer), women were left out of research.

That began to change when the National Institutes of Health (NIH) created the Office of Research on Women’s Health in 1990 – but it took an act of Congress in 1993 for NIH to include women and minorities in all researched populations. Still, concerns remain about the extent of women’s inclusion in medical trials and research in general.

We need to build on our progress on women’s health – which includes passing the Robin Danielson Act. American women deserve the ability to make informed decisions when buying feminine hygiene products. Though not always a topic we hear about, women’s health is always a conversation worth having in our homes, in our communities and in the halls of Congress.