Menstrual products used by millions of South Africans may contain hormone-disrupting chemicals, even when marketed as “free from harmful chemicals”, according to new research from the University of the Free State (UFS). The findings raise concerns about potential long-term health risks, including an increased risk of serious illnesses such as cancer.
Published in the journal Science of the Total Environment, the study found that every sanitary pad and pantyliner tested contained at least two endocrine-disrupting chemicals (EDCs), raising concerns about consumer safety, transparency and long-term exposure.
The research was conducted by a UFS team, including Janine Blignaut (PhD candidate), Dr Gabre Kemp (Department of Microbiology and Biochemistry), Prof Elizabeth Erasmus (Department of Chemistry), Prof Deon Visser (head of the Department of Chemistry) and Prof Marietjie Schutte-Smith (Department of Chemistry).
“Our study highlights a concerning reality regarding the safety of menstrual products,” said Visser.
“Many sanitary pads and liners contain hormone-disrupting chemicals, even when they are marketed as being ‘free from harmful chemicals’.”
Chemicals found across all products tested
The UFS research team analysed 16 brands of sanitary pads and eight types of pantyliners (such as Always, Kotex, Libresse, Lil-lets and Stayfree), popular in South African retail stores. The study focused on three groups of endocrine-disrupting chemicals (EDCs) namey phthalates, bisphenols (including BPA) and parabens.
The findings showed widespread contamination across all products tested. Every single pad and liner contained at least two of the target chemicals.
The findings showed widespread contamination across all products tested. Every single pad and liner contained at least two of the target chemicals, bisphenols were detected in 100% of sanitary pads and 75% of pantyliners, while parabens were found in more than 81% of pads and 75% of liners.
Phthalates were present in all pantyliners tested and in 50% of sanitary pads.The researchers note that these substances are not always added intentionally, but may migrate into products from plastics, adhesives and manufacturing processes.
“The heat-pressing process can cause these chemicals to move into the top layer that touches your skin,” Visser explained.
Why long-term exposure matters
Although the levels detected in a single product may appear small, the researchers emphasise that the concern lies in repeated exposure over time.
Menstrual products come into contact with mucosal tissue, which absorbs chemicals more quickly and directly than normal skin. Most individuals use these products for several days each month over several decades.
This repeated contact may contribute to cumulative exposure, which has been linked to hormonal imbalances, fertility problems, endometriosis and even certain types of cancer.
Limited regulation and lack of disclosure
The study also highlighted gaps in chemical regulation in South Africa.
“The South African Bureau of Standards (SABS) does have the South African National Standards (SANS) 1043 test,” Visser said, “but it tests only for microbiology, absorbency and so on. According to our knowledge, there are no standards regarding the chemicals we observed.”
Manufacturers are also generally not required to disclose the full chemical composition of menstrual products.
“We do believe that manufacturers should disclose all chemicals in their products, even if they fall below daily limits,” he added.
Practical steps and future solutions
Visser advises consumers to look for products certified under the OEKO-TEX Standard 100, or to consider reusable alternatives.
“Look for the OEKO-TEX Standard 100 verification — an international standard — or use a reusable sanitary towel,” he said.
This research forms part of a broader UFS initiative addressing menstrual health and access.
“Our research started off several years ago when we discussed a radio programme that mentioned that many young girls do not have access to feminine products,” Visser said. “We decided to get involved.”
The interdisciplinary team is now working on new innovations.
“Our team is in the process of developing a reusable sanitary pad with superpowers, antimicrobial properties,” Visser added.
A call for transparency
The researchers said the findings underscore the need for clearer labelling, stronger chemical standards and continued monitoring of everyday menstrual products.
“This study serves as a wake-up call that current regulations and ‘clean’ labels in South Africa may not be providing the protection consumers expect,” Visser said.
