Sanitary products are quietly one of the biggest waste stories no one talks about.
Globally, we generate over 2 billion tonnes of sanitary waste each year, mostly from single-use pads and baby diapers. These products are packed with plastics and super-absorbent polymers that don’t just “break down” - they can sit in landfills for up to 800 years. Really not great.
So yeah, I’m anxious about menstrual products - but not in a conspiracy way. In a “I read the papers” way. When you actually dig into the research, you realise how little transparency there’s been around what’s in pads and tampons. For years, ingredient disclosure was limited, and independent testing was rare. Then in 2024, researchers published what may be the first study to systematically measure metals in tampons. They detected multiple metals across products tested - including trace levels of toxic elements like arsenic and lead.
Important context: detection doesn’t automatically equal harm. Dose, exposure pathway, and bioavailability matter (a lot). But finding these metals at all raises real questions about raw materials, manufacturing processes, and regulation - especially for products used internally and repeatedly over decades. I’m not here to tell you what to use. I just want to break down the science so you can decide for yourself what feels safe, sustainable, and right for your body.
The researchers tested multiple brands and different types of tampons - including organic ones. And here’s the part that genuinely made me pause: every single brand tested contained detectable metals. Lead concentrations were higher in non-organic tampons. But arsenic? Higher in some of the organic ones. How scary is that?
Before we spiral - a few important science brakes need to be pumped here.
First: “detectable” doesn’t automatically mean “dangerous.” Modern lab equipment can detect metals at incredibly tiny concentrations - parts per billion or even trillion. The key question isn’t just is it there? It’s:
- At what concentration?
- Can it leach out?
- Can it be absorbed through vaginal tissue?
- And if so, at what dose does it become harmful?
Those are the questions toxicologists care about. So how do metals even end up in tampons?
There are actually several plausible pathways. Cotton is a bioaccumulator, meaning it can absorb substances from soil and water. If cotton is grown in soil contaminated by industrial activity - say near a former mining site or lead smelter - trace metals can be taken up during growth. Organic farming doesn’t automatically mean contaminant-free soil; it just refers to pesticide and fertiliser practices.
Then there’s manufacturing. Cross-contamination during processing, contact with machinery, bleaching agents, or antibacterial treatments could all theoretically introduce trace metals. Even packaging can play a role. Industrial systems are complex, and trace contamination isn’t unusual across many consumer goods - from food to cosmetics.
The (kind of?) reassuring part
We don’t actually know yet whether these metals negatively impact health in this context. It’s not currently clear whether the metals:
- Leach out during use
- Become bioavailable (meaning the body can absorb them)
- Or reach concentrations high enough to cause harm
And you’re right - a tampon is designed to absorb, not release. But the vaginal canal is also a highly vascularised tissue with efficient absorption potential. That’s why certain medications can be delivered vaginally. So the exposure pathway is biologically plausible - we just don’t have the full data yet. And that’s the real issue here: the research gap.
We have decades of widespread tampon use. Millions of people using them monthly. And only recently are we beginning to systematically test what’s actually in them. That doesn’t mean panic. It means we need better regulation, better transparency, and more independent research. Science isn’t about fear - it’s about evidence. And right now, we’re still collecting it.
Okay but let’s talk about the plastic. Because when you look at a pad or tampon, your brain goes: cotton = biodegradable = chill.
Not exactly.
What are we actually throwing away?
In 2018 alone, people in the U.S. bought 5.8 billion tampons. Over a lifetime, one person who menstruates will use somewhere between 5,000 and 15,000 pads and tampons. The majority? Straight to landfill. And here’s the plot twist: they’re not just cotton.
Modern pads and tampons are layered products engineered for leak-proofing, absorption, and durability. That engineering relies heavily on plastics - mainly polyethylene (PE) and polypropylene (PP).
- The top sheet of many pads is made from PP or PE (that smooth, dry-feeling layer).
- The leak-proof backing is typically a thin PE or PP film.
- Adhesive strips and wings? Also plastic-based.
- Some pads contain polyester fibres to enhance absorbency.
- Tampons with plastic applicators are usually made from PP or PE.
- Even “cotton” tampons can contain plastic components in the string, wrapper, or applicator.
On average:
- Pads are typically 35–60% plastic.
- Some estimates suggest an average sanitary napkin contains around 39% PE.
- Tampons can contain roughly 30% plastic, especially with plastic applicators.
A single pack of pads can contain as much plastic as four plastic bags.
That’s not biodegradable. That’s long-term polymer persistence.
How on Earth did we get here???
Pads have existed since the late 1800s, but by the mid-20th century manufacturers began adding thin, flexible, leak-proof PP and PE layers. Adhesive backing was introduced to help pads stick to underwear, and by the 1970s, wings were added for extra stability. Around the 1930s, plastic tampon applicators entered the market.
What started as cotton-based absorbency evolved into multilayer plastic composites designed for convenience - and disposability.
And where does it all go?
Most sanitary waste ends up in landfill. But not all of it. Sanitary products are now recognised as a source of microplastic pollution, especially when improperly disposed of (yes, flushing is a big problem). When plastic-based materials like PP, PE, and polyester degrade, they fragment into microplastics. In the Euro-Mediterranean region, sanitary items (including wipes, cotton buds, and sanitary towels) account for about 25% of plastic debris in some coastal sediments. Across European seas, hundreds of thousands of tonnes of macro- and microplastics enter marine environments each year.
And here’s something wild: the contribution of sanitary products to marine microplastics has likely been underestimated. Why? Because many of the fibres are white - and traditional microplastic analysis often uses white filtration backgrounds. They’re literally harder to see.
A major driver of this pollution is improper disposal - products flushed instead of placed in bins. That leads to sewage-related debris washing into rivers and coastal systems. So when we talk about menstrual products, we’re not just talking about personal health. We’re talking about polymer chemistry, waste systems, marine ecology, and long-term environmental persistence. It’s not about guilt. It’s about understanding what “disposable” actually means in a world where PE and PP don’t disappear - they just get smaller.
Periods are natural. Plastic pollution isn’t.
The more we understand about what’s in our products - from trace metals to PE and PP - the more power we have to choose differently, demand transparency, and push for better design. Also, science isn’t here to scare you. It’s here to help you decide what kind of impact you want to leave behind.