The PFAS Problem: Why Your "Organic" Period Products Might Be Toxic AF

And what you can actually do about it.

Here's a fun fact nobody tells you: the period products marketed as "natural," "organic," and "non-toxic" might be poisoning you.

This month, Thinx—the period underwear company that built its entire brand on being a "better" alternative—settled a class action lawsuit for $5 million. The charge? Misleading customers by claiming their products were safe and non-toxic when they actually contain PFAS.

PFAS are "forever chemicals" that never break down, accumulate in your body over time, and are linked to cancer, infertility, thyroid problems, and a laundry list of other health issues.

And here's the kicker: Thinx isn't alone. Recent independent lab testing found PFAS in nearly two-thirds of period underwear brands, almost half of menstrual pads and panty liners, and a quarter of tampons—including products labeled "organic."

So let's talk about what PFAS actually are, why they're in your period products, what health risks they pose, and—most importantly—how to protect yourself when the FDA clearly isn't doing its job.

WTF Are PFAS?

PFAS stands for per- and poly-fluoroalkyl substances—a group of at least 4,730 synthetic chemicals that contain fluorine.

They've been used since the 1950s in thousands of products you probably use daily:

🐾 Non-stick cookware (Teflon)
🐾 Waterproof clothing
🐾 Stain-resistant fabrics and carpets
🐾 Food packaging (microwave popcorn bags, fast food wrappers)
🐾 Cosmetics (foundation, mascara, body lotion, shampoo, sunscreen)
🐾 Dental floss
🐾 And apparently, your tampons and period underwear

Why They're Called "Forever Chemicals"

PFAS never break down in the environment. Ever.

They're found in:

Polar bears in the Arctic
Penguins in Antarctica
The drinking water of almost every state in the U.S.
The blood of basically every American, including yours

Once PFAS enter your body, they accumulate over time (this is called bioaccumulation). Your body can't efficiently eliminate them, so they just... stay there. Building up. For decades.

The Regulatory Shuffle

The most commonly studied PFAS—PFOA and PFOS—were phased out in the U.S. between 2002-2015 after research revealed they're toxic as hell.

But here's the thing: "phased out" doesn't mean "gone."

Because these chemicals are so persistent:

They're still in our soil and water
They're still in older products (like that Teflon pan from 2010)
They're still in products imported from countries where they're legal
They've been replaced by newer short-chain PFAS that haven't been well studied and may be just as harmful

Translation: The chemical industry just swapped one set of dangerous compounds for another set of potentially dangerous compounds, called them "new and improved," and kept selling them to us.

It's one of these newer PFAS that was found at high levels in Thinx underwear.

Why Are PFAS in Period Products?

Great question. Nobody fucking knows for sure.

Manufacturers claim they never "intentionally" added PFAS. Thinx maintains that "PFAS has never been part of the brand's product design."

So how did it get there?

Possible explanations:

Contaminated raw materials – The cotton, fabrics, or other materials used in production are already contaminated with PFAS from industrial processes or contaminated water/soil
Manufacturing processes – PFAS might be used in waterproofing, moisture-wicking, or antimicrobial treatments during production
Packaging and processing – PFAS in packaging materials or industrial equipment could transfer to products
"We have no idea and aren't telling" – Companies genuinely might not know (or care) what's in their supply chain

Here's the real problem: Manufacturers aren't required to disclose all ingredients in menstrual products.

Menstrual products—tampons, pads, period underwear, menstrual cups—are classified by the FDA as "medical devices."

You'd think that means stricter regulations, right?

Nope. The opposite.

Medical devices actually undergo less scrutiny than cosmetics. They require little to no safety testing before hitting the market, and unlike cosmetics, manufacturers don't have to tell you what's in them.

So even if you're an educated consumer reading every label, you literally cannot know what chemicals are in your period products because companies aren't required to tell you.

What Else Is Hiding in Your Tampons and Pads?

PFAS aren't the only concerning chemicals potentially lurking in menstrual products.

A study called "Chem Fatale" by Women's Voices for the Earth found that tampons and pads can contain:

🚫 Dioxins (from bleaching process)
🚫 Furans
🚫 Pesticide residues
🚫 Unknown fragrance chemicals
🚫 Adhesive chemicals like methyldibromo glutaronitrile

None of these are listed on the packaging.

A 2022 review of nearly two dozen studies measuring toxins in menstrual products concluded that all the studies detected toxins. Some found significant levels; others concluded levels were low enough to pose little risk.

But here's the thing: We don't actually know how safe or unsafe these exposure levels are because the research is woefully inadequate.

Consider this: The average menstruator uses over 10,000 menstrual products in their lifetime.

That's 10,000+ exposures to unknown chemicals through highly absorbent vaginal tissue over decades.

And whatever gets absorbed doesn't just affect you—it can impact your fertility and be passed to your children.

I'd say further research is urgently warranted. Wouldn't you?

How Much PFAS Are You Actually Absorbing?

The honest answer: We don't know.

The lawsuit against Thinx charged them with misleading marketing—not necessarily with harming users.

That's because no studies have been done on how much PFAS from period products is actually absorbed into the bloodstream.

Here's what we do know:

🐱 Vaginal/vulvar tissue is highly absorbent

Much more so than regular skin. That's why vaginal medications work so well—and why exposure to chemicals through this tissue is particularly concerning.

🐱 Dermal absorption of PFAS is harmful

A recent study on mice found that absorbing PFOA through skin was as harmful as ingesting it orally.

Studies on similar chemicals (like brominated flame retardants) show that dermal absorption can be a significant exposure source in humans.

🐱 Washing period underwear might make it worse

Some researchers suggest washing period panties will remove PFAS over time.

Great, except then those "forever chemicals" end up in our water and environment.

And a Greenpeace study found that concentrations of PFAS actually increased in waterproof clothing after it was weathered compared to new items.

Plus, you obviously can't pre-wash tampons and pads.

🐱 It might be minimal compared to other sources

Period products might contribute less PFAS exposure than:

Drinking water (contaminated in almost every state)
Food (via contaminated soil and packaging)
Cookware, cosmetics, and other consumer products

The EPA recently updated its guidelines, saying that the "safe" limit for PFOS should be 0.02 parts per trillion and for PFOA should be 0.004 ppt.

Their previous limit was 70 ppt.

That's a decrease of more than a thousandfold based on new research showing even tiny amounts are harmful.

At least 100 million Americans have drinking water exceeding even the old, much weaker limit.

Bottom line: We're getting PFAS from everywhere, and period products are just one more source of exposure we shouldn't have to deal with.

The Health Risks of PFAS

The FDA claims that just because a product has "detectable" PFAS doesn't mean it's unsafe.

But when it comes to endocrine-disrupting chemicals like PFAS, that's bullshit.

Studies show that chronic exposure to even barely measurable amounts can be harmful because it only takes amounts measured in parts-per-million to fuck with your hormones.

🚨 PFAS Are Linked To:

Cancer:

Kidney cancer
Testicular cancer
Breast cancer
PFOA is classified as a potential carcinogen

Metabolic & Cardiovascular Issues:

Increased cholesterol
Obesity
Type 2 diabetes
Changes in liver enzymes

Immune System Damage:

Decreased vaccine response in children
Neurotoxic and immunotoxic effects
Possibly associated with more severe COVID (they accumulate in lungs)

Reproductive & Hormonal Problems:

Menstrual irregularities
Ovarian dysfunction
PCOS (polycystic ovarian syndrome)
Endometriosis
Thyroid hormone deficiency
Fertility issues
Earlier menopause

Pregnancy & Birth Outcomes:

Impacts thyroid function, metabolism, and immunity in both mother and child
Lower birth weight
Increased risk of preterm birth
Higher risk of gestational diabetes
Higher risk of pre-eclampsia
Increased risk of childhood obesity and infections in babies

The Kicker? This Isn't New Information

The FDA has known about PFAS health risks since the 1960s.

DuPont—who first developed PFOA—submitted evidence of harm to the FDA in 1966.

That's right. The government has known for nearly 60 years that these chemicals are dangerous, and they're still letting companies put them in products that touch your most vulnerable tissue for days at a time, every single month.

If you haven't seen the 2019 movie Dark Waters with Mark Ruffalo about DuPont's PFOA coverup, watch it. It's infuriating.

How to Reduce Your PFAS Exposure

Look, it's impossible to avoid PFAS completely. They're too ubiquitous.

But you can reduce your personal body burden by minimizing exposure where possible.

✔️ Filter Your Drinking Water

Use an activated carbon or reverse osmosis filtration system. This is probably the single most impactful thing you can do.

✔️ Ditch Non-Stick Cookware

Switch to stainless steel, enamel, glass, or cast iron.

✔️ Avoid Stain and Water-Resistant Products

This includes:

Stain-resistant carpets and furniture
Waterproof clothing (unless truly necessary)
Stain-repellent sprays

The Green Science Policy Institute has lists of PFAS-free consumer products if you need rain gear, car seats, etc.

✔️ Skip Takeout Containers When Possible

If you do use them, transfer food out immediately and never reheat food in the container.

✔️ Check Cosmetics and Personal Care Products

Avoid anything with "PTFE" or "fluoro" in the ingredients.

The Environmental Working Group's database can help you identify PFAS-free products.

What to Do About Period Products

🐱 If You Love Period Underwear:

Check out guides from Better Goods and Mamavation to find PFAS-free options.

Not all period underwear contains PFAS—but you need to do your homework because companies won't volunteer this information.

🐱 Try Menstrual Cups or Discs

These are typically made with body-safe silicone and collect your flow rather than absorbing it.

You empty, rinse, and reuse—which also eliminates the waste problem.

🐱 Choose Organic Tampons and Pads (But Stay Vigilant)

Look for companies that:

Disclose all ingredients
Have third-party testing
Don't use the words "organic" and "natural" as empty marketing bullshit

Remember: PFAS were found in products marketed as "organic," so the label alone doesn't guarantee safety.

🐱 Consider Reusable Organic Cotton Pads

Yes, it's extra work. But for days when you're home or overnight, washable organic cotton pads eliminate both waste and chemical exposure.

One Tiny Silver Lining

Here's something weirdly positive: Because PFAS accumulate in your blood, menstruators may actually have slightly lower PFAS levels than non-menstruators.

Why? Because we eliminate a small amount with each period.

So there's that. Every time you change a tampon, you're detoxing forever chemicals.

You're welcome for that fun fact.

We Need Systemic Change, Not Personal Responsibility

Here's what pisses me off most about this entire situation:

The burden shouldn't be on individuals to police every product, scrutinize every label, and attempt the impossible task of avoiding ubiquitous toxins.

We need:

🔥 Better Research

We need more studies on:

Health effects of PFAS generally
Specific risks from toxins in menstrual products
How much PFAS is absorbed through vaginal tissue
Long-term health impacts of chronic low-level exposure

🔥 Actual Regulation

The FDA and EPA need to:

Require product testing and transparency
Mandate full ingredient disclosure on all menstrual products
Stop allowing companies to claim products are "non-toxic" without proving it
Phase out PFAS production entirely

🔥 The Precautionary Principle

When scientific evidence about a health hazard is uncertain but the stakes are high, decision-makers should adopt precautionary measures.

Translation: We don't need to wait for definitive proof that PFAS in tampons causes cancer before we remove PFAS from tampons.

There's enough evidence of harm to act now.

🔥 Ingredient Transparency Laws

New York (2019) and California (2023) now require menstrual products to disclose all intentionally added ingredients.

Every state needs these laws.

But even these don't go far enough—companies like Thinx can still claim they didn't "intentionally" add PFAS, so they're off the hook for disclosure.

The Bottom Line

Your period products—even ones marketed as "organic," "natural," and "non-toxic"—may contain forever chemicals that accumulate in your body and are linked to cancer, infertility, and hormonal disorders.

The FDA has known PFAS are dangerous for 60 years and still doesn't require companies to test products or disclose ingredients.

You deserve better.

You deserve to know what's in products that touch your most absorbent tissue for days at a time, every month, for decades.

You deserve accurate information to make informed choices about what goes in and on your body.

And you deserve a government that actually protects you instead of protecting corporate profits.

Until that happens, do what you can to minimize exposure, demand transparency from companies, and support legislation requiring full ingredient disclosure.

Your health is worth it.

— Meghan Carozza
Co-Founder & Chief Experience Officer, Good Kitty Co.

References:

Ding N, et al. "Perfluoroalkyl and polyfluoroalkyl substances (PFAS) and their effects on the ovary." Hum Reprod Update. 2020.
Upson K, et al. "Menstrual Products as a Source of Environmental Chemical Exposure." Curr Envir Health Rpt. 2022.
Ragnarsdóttir O, et al. "Dermal uptake: An important pathway of human exposure to perfluoroalkyl substances?" Environmental Pollution. 2022.
Mokra K. "Endocrine Disruptor Potential of Short- and Long-Chain Perfluoroalkyl Substances (PFASs)." Int J Mol Sci. 2021.

Note: This article is for educational purposes. Good Kitty Co. focuses on UTI prevention, not menstrual products, but we believe all women deserve transparency about what's in products designed for their bodies.

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