Groundbreaking University of the Free State research reveals endocrine-disrupting chemicals in every sanitary pad and pantyliner tested — including products marketed as chemical-free.
Millions of South African women may be unknowingly exposed to hormone-disrupting chemicals through everyday menstrual products, according to new research from the University of the Free State (UFS) — the first study of its kind conducted on feminine hygiene products in the country.
Published in the peer-reviewed journal Science of the Total Environment on 25 February 2026, the study found that every sanitary pad and pantyliner tested contained at least two endocrine-disrupting chemicals (EDCs), raising serious questions about product safety, labelling transparency, and the health risks of long-term exposure.
What the Researchers Tested
The UFS team analysed 16 brands of sanitary pads and eight types of pantyliners commonly available in South African retail stores. They focused on three well-known groups of endocrine-disrupting chemicals: phthalates, bisphenols (including BPA), and parabens — all substances linked to hormonal interference in the human body.
The results were consistent and widespread. Not a single product tested was free of contamination. Bisphenols were detected in 100% of sanitary pads and 75% of pantyliners. Parabens showed up in more than 81% of pads and 75% of liners. Phthalates were present in all pantyliners tested and in half of all sanitary pads examined.
Crucially, some of the affected products were marketed as being “free from harmful chemicals” — a claim the research directly contradicts.
How These Chemicals End Up in Period Products
The researchers note that these substances are not always deliberately added during manufacturing. Instead, they can migrate into finished products from plastics, adhesives, packaging materials, and production equipment.
“The heat-pressing process can cause these chemicals to move into the top layer that touches your skin,” explained Professor Deon Visser, head of the Department of Chemistry at UFS and lead voice on the study.
This means that even manufacturers committed to cleaner formulations may be inadvertently exposing consumers to harmful compounds through their production processes.
Why Repeated Exposure Is the Real Concern
While the concentration of EDCs detected in any single product may seem low, the researchers stress that cumulative exposure over time is where the real risk lies. Menstrual products are worn directly against mucosal tissue — a type of skin lining that absorbs chemicals significantly faster and more efficiently than ordinary skin.
Most women use these products for several days each month, across several decades of their lives. That adds up to thousands of hours of direct skin contact with materials that may contain hormone-interfering substances.
Long-term exposure to EDCs has been associated with hormonal imbalances, fertility complications, endometriosis, and an increased risk of certain cancers. The researchers are careful not to overstate causation, but emphasise that the pattern of repeated exposure warrants serious attention.
South Africa’s Regulatory Gap
The study also shines a light on significant gaps in South African chemical safety regulation as it applies to menstrual products. While the South African Bureau of Standards (SABS) does maintain a testing standard for feminine hygiene products — SANS 1043 — this standard currently only covers microbiological safety and absorbency performance.
“According to our knowledge, there are no standards regarding the chemicals we observed,” said Professor Visser.
Compounding the problem, manufacturers are not legally required to disclose the full chemical composition of their products, meaning consumers have no reliable way to make informed choices based on ingredients alone. The research team is calling for that to change.
“We believe manufacturers should disclose all chemicals in their products, even if they fall below daily limits,” Visser said.
What Consumers Can Do Right Now
While regulatory reform takes time, Professor Visser offered practical guidance for consumers concerned about their exposure. He recommends looking for products certified under the OEKO-TEX Standard 100, an internationally recognised textile safety certification that tests for a broad range of harmful substances.
He also encourages consumers to consider switching to reusable menstrual products, such as menstrual cups or washable cloth pads, which reduce both chemical exposure and environmental waste.
What Comes Next
This research forms part of a wider UFS initiative focused on menstrual health, access, and innovation. The interdisciplinary team is already working on what could be a significant development in period care: a reusable sanitary pad with built-in antimicrobial properties.
“We are in the process of developing a reusable sanitary pad with superpowers — antimicrobial properties,” Visser said.
Beyond product innovation, the team is calling for stronger chemical safety standards specific to menstrual products, clearer and more honest product labelling, and ongoing independent monitoring of the period products available to South African consumers.
