For millions of women, inserting a tampon is as routine as taking a shower. But a new study by the University of La Plata in Argentina found that at least 85 percent of tampons, cotton balls, and sanitary products tested contained glyphosate, a chemical ruled as a likely carcinogen by the International Agency for Research on Cancer (IARC) at the World Health Organization (WHO).

One of the leading researchers of the Argentine study called the results of the research "very serious."

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“When you use cotton or gauze to heal wounds or [for personal hygienic uses] thinking they are sterilized products, [the result is that they are] contaminated with a carcinogenic substance,” said pediatrician Vazquez Medardo Avila. His comments are translated from Spanish to English by the Huffington Post.

WHAT IS THE CHEMICAL?

According to the National Pesticide Information Center (NPIC), glyphosate is a herbicide used for various reasons, including the regulation of plant growth and fruit ripening. The NPIC notes that the chemical is one of the most widely used herbicides in the United States, with more than 750 products containing the chemical for sale in the U.S.

Glyphosate is “definitely genotoxic,” meaning that it damages DNA, according to Professor Chris Portier, a co-author of the IARC’s report classifying the chemical as a “probable carcinogen.”

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Scientific American also notes that the IARC review hasn’t found glyphosate as a direct cause of cancer in humans, but classified glyphosate as a probable carcinogen because of evidence linking the chemical with tumors in mice and rats.

HOW DOES THE CHEMICAL GET INTO TAMPONS?

The Huffington Post reports that the study shows genetically modified cotton (GMO) is sprayed with glyphosate, which is then passed into the product.

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HOW CAN I FIND OUT WHAT’S IN MY TAMPONS?

Unfortunately, you can’t. As a Harvard Law School paper notes, the FDA doesn't require manufacturers to provide ingredient labeling.

“In its final rule for absorbency labeling, the FDA responded [that it] lacked the authority to mandate ingredient labeling [on tampons]," the paper reads.

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In a call for the FDA and the feminine hygiene industry to report what's in the products, Congresswoman Carolyn Maloney (D-N.Y.) wrote in the Guardian earlier this year that significant amounts of data reporting the effects of toxins in tampons "does not exist." This means that if prolonged use of tampons has negative health effects, there's no way to scientifically show it.

“Imagine if we only examined the health effects of smoking a single cigarette," Maloney writes.

If you don't want to use regular pads or tampons, there are alternatives, which may be more expensive. Check out some options like a sea sponge or a Diva cup that you can use to catch menstruation here.