The vaginal mucosa is not like the skin on your arm. It's highly vascular, has no sweat glands or sebaceous glands to act as additional barriers, and absorbs substances directly into the bloodstream at a rate that significantly exceeds skin absorption. This makes it one of the most sensitive sites of chemical exposure on your body.
Conventional tampons and pads spend hours in direct contact with this tissue, every month, for decades. The almost complete lack of mandatory ingredient disclosure for period products is one of the more glaring gaps in consumer safety regulation.
◈Key Facts
What conventional products can contain
Pesticide residue
Conventional cotton is treated with a significant chemical load — herbicides, insecticides, and fungicides throughout the growing process. Glyphosate, the most widely used herbicide globally, has been detected in conventional tampon cotton. The question of how much residue remains after processing and what the health implications are of repeated internal exposure is largely unstudied, which is itself the problem.
Dioxins from chlorine bleaching
Historically, the bright white of conventional period products came from chlorine bleaching, which produces dioxins as a byproduct. Dioxins are persistent organic pollutants that accumulate in body fat and are associated with hormonal disruption, immune effects, and carcinogenicity.
Most major manufacturers have switched to elemental chlorine-free (ECF) or totally chlorine-free (TCF) processing, which significantly reduces but does not eliminate dioxin formation. Independent testing has found dioxin residues in some conventional products. Given the reproductive and hormonal sensitivity of the tissue in contact with these products, "significantly reduced" is a different standard than "none."
Synthetic fibres and additives
Many pads and liners contain synthetic materials — polyester, rayon, polyethylene — in addition to or instead of cotton. Some contain odour-neutralising additives, moisturising agents, or plastic leak-proof barriers. The contents of these materials are generally not disclosed and vary by brand and product line.
Fragrances
Scented period products contain compounds. See the article for why this is a particular concern — but the short version is that can contain phthalates and other endocrine-disrupting compounds, and applying them to highly absorptive tissue for extended periods is precisely the exposure scenario you want to avoid.
Period underwear and PFAS
Period underwear uses moisture-wicking, leak-resistant fabric — properties that have historically been achieved using PFAS (polyfluoroalkyl substances), the "forever chemicals" discussed in the endocrine disruptors article.
Testing conducted by various organisations has found PFAS in period underwear from multiple brands. Some brands have since removed PFAS from their products and reformulated. If you use period underwear, look for brands that have explicitly tested and confirmed their products are PFAS-free — ideally with third-party testing documentation.
Menstrual cups and discs
Medical-grade silicone cups and discs are among the cleanest options available. Medical-grade silicone is inert — it doesn't leach, doesn't contain pesticides or bleaching residues, and doesn't require replacement. The main variables are manufacturing quality and ensuring you're buying from a reputable brand using genuinely medical-grade silicone rather than a cheaper variant.
The adjustment period is real, but for people who find cups workable they represent a significant reduction in both chemical exposure and ongoing waste.
Organic cotton products
Certified organic cotton — particularly to GOTS (Global Organic Textile Standard) — avoids synthetic pesticides and fertilisers in the growing process and has cleaner processing requirements. This is a meaningful improvement over conventional cotton, though it doesn't address all concerns (synthetic materials used alongside cotton, bleaching methods, additives).
For tampons specifically, look for organic cotton with TCF (totally chlorine-free) processing, no fragrances, and no plastic applicator if you want the cleanest option in this format.
What the "organic" label means and doesn't mean
"Organic cotton" on a product label tells you the cotton itself was grown organically. It doesn't necessarily tell you about the processing, the bleaching method, synthetic components that might be included, or whether fragrances or additives have been used. GOTS certification covers the full production chain and is a more meaningful standard.
You're using period products for roughly 40 years of your life. The cumulative exposure from monthly direct internal contact adds up in a way that single-use product comparisons understate.