Unexpected exposure sources

How diapers and menstrual pads are exposing babies and women to toxic chemicals

Brian Bienkowski for Environmental Health News

Most diapers and sanitary pads contain volatile organic compounds and phthalates and with this continued, long-term exposure a significant amount of these harmful chemicals could be absorbed via the genitals, according to a new study.

The study was spurred by an investigation from South Korean media outlets in 2017 that found new sanitary pads might be causing menstrual problems and irregularities and was broadened to the U.S. and other countries. 

More than 15,000 women complained and signed onto a class action lawsuit claiming harm from menstrual pads by the company Lillian. The pads were removed from the market. Women alleged rashes, infections, irregular periods and bad cramping.

Scientists and advocates say the exposure uncovers a gap in our regulation of baby's diapers and is emblematic of our society's historical unease with having productive conversations about women's reproductive health.

"The physical location of the exposure site, the high absorption rate of the genitalia for chemicals, and the long-term exposure period demand a thorough investigation on the potential impact of the exposure to VOCs and phthalates," the authors wrote in the study, which will be published in Reproductive Toxicology.

Exposure to VOCs increases the risk of brain impairment, asthma, disabilities, certain cancers, and the proper functioning of the reproductive system. 


Phthalates, used as plasticizers in products such as cosmetics, toys, medical devices and other plastics, have been linked to a variety of health concerns including endocrine disruption, impacts to the heart and reproductive systems, diabetes, some cancers, and birth defects.

Both sanitary pads—absorbent pads worn by women during menstruation—and diapers are made of synthetic plastics. The scientists tested a handful of brands from each product for certain VOCs — methylene chloride, toluene, and xylene—and four types of phthalates. 

The study does not name the brands tested, but the products were collected from markets in Korea, Japan, Finland, France, Greece and the United States.

For VOCs, the researchers found methylene chloride in two brands of sanitary pads; toluene in nine; and xylene in all 11 brands tested. In diapers, all four brands tested contained toluene and xylene, none contained methylene chloride.

For phthalates, the researchers found two types of the chemicals in all 11 brands of sanitary pads tested. In diapers, all four brands contained two types of phthalates, and another type of phthalate was found in one brand. The products had significantly higher levels of phthalates than what is commonly found in plastic goods.

Jay Ko CheMyong, senior author of the study and professor & director of Graduate Studies, at Department of University of Illinois at Urbana-Champaign's College of Veterinary Medicine, told EHN he had concerns about outing the brands and "just wanted to provide objective numbers as a scientist."

Alexandra Scranton—director of Science and Research for Women's Voices for the Earth, which focuses on women's voices and roles in eliminating the toxic chemicals from products— pointed out "major differences between different brands" when it came to the levels of the compounds.

"There was a nearly 6,000-fold difference in levels [of VOCs]," she told EHN. 

"It tells you that there are a variety of ways these pads are being made – it's not general uncontrolled contamination, there's something intentionally being done" during manufacturing. Scranton was not involved in the study.

For phthalates, there was a 130-fold difference between the highest levels in the pads and the lowest.

CheMyong said phthalates are used to soften plastics, while VOCs are used as dissvoling agents in plastic manufacturing.

"Sadly, this is not surprising, but is quite concerning given the contact with reproductive organs," Dr. Leo Trasande, a professor in the Departments of Pediatrics, Environmental Medicine and Population Health at New York University's Langone Health, told EHN.

"The reality here is that these are very recently collected samples and, as much as there's been a focus on phthalates in toys and contact with kids through their mouth, this raises serious concerns and a need for regulation in these products," he said.

Trasande was not involved in the study but is a renowned leader in children's environmental health and just wrote a book, Sicker, Fatter, Poorer, about the urgent threat of hormone disrupting chemicals such as phthalates. 

He said few studies have looked at infant exposures to these chemicals, however, exposure directly to the genitals is worrisome since phthalates inhibit the male sex hormone testosterone and prenatal exposure has been associated with abnormal genital development in boys.

"And these exposures are during a critical window on genital development as well as other organs," Trasande said.

Children health advocates have for years asked for stricter regulation of baby diapers, which are not considered medical devices by the FDA and therefore not required to go through medical testing to prove their safety.

"That's chronic exposure"

As for the sanitary pads, one health concern is the sheer amount of exposure, Ami Zota, an assistant professor in the Department of Environmental & Occupational Health at the George Washington University Milken School of Public Health, told EHN.

"Women are using these products from the age of 12, maybe younger, and almost until 50 – that's like four decades … once a month," said Zota, who was not involved in the study but whose research focuses on social disparities, environmental exposures, and reproductive and children's health.

"That's chronic exposure," she added.

Laura Strausfeld — co-founder of Period Equity, an organization focused on the affordability, safety and availability of menstrual products — told EHN historically there's been more concern over the compounds in tampons, since they're inserted into the vagina. Strausfeld was not involved in the study.

But increasingly there is more focus on what harm pads may be causing, she said, as "we've really come to appreciate in the last decade or so that the vagina and genitalia are very effective at absorbing" toxics.

Zota said, while the research still isn't settled, it's possible that there may be greater absorption through the vagina than other body parts as contaminants could travel up the reproductive tract.

She pointed to her own research that found an association between vaginal douching use and higher phthalate levels.

Scranton said a main issue for women's menstrual products, much like diapers, is the lack of disclosure of ingredients.

She also pointed out that the limited industry studies often don't take into account chemicals' volatility and only look at potential exposure from the top layer of pads.

The lack of research and conversation around the health impacts of menstrual products "is the historical and cultural taboo in talking about the vagina," Strausfeld said.

However, there seems to be something of a cultural shift. "There are more and more bills passed at the state and federal level to supply menstrual supplies to women who can't afford them or are in prison, or in school," she said. "We're finally starting to talk about this more."

But, she adds, this new study begs the question: "What should we be looking at that we haven't been looking at? It seems clear that companies are regularly innovating new products to make them more absorbent and flagrantly using materials and new synthetic plastics that we need to be concerned about."