Here is a sentence you never expected to read about the "green" swap you felt good about: scientists dropped nine paper straws into fizzy soda, warmed it, left it half an hour, and watched a suspected carcinogen leak out, at a level above its legal safety limit. Paper straws are toxic, and the research meant to vindicate them has quietly convicted them instead. Forever chemicals turned up in roughly 90% of paper straw brands tested in Europe. The straw you chose to save the ocean may be the dirtiest thing in your glass, and the honest fix takes about ten seconds.
A Carcinogen In Your Soda
Start with the finding that should make you set the straw down. In 2024, a Spanish team ran the test almost everyone else had skipped: instead of merely scanning a dry straw, they put nine paper straws (some printed, some plain) into a carbonated soft drink, held it at 70°C for 30 minutes, and measured what ended up in the liquid (Study). Nineteen separate compounds migrated into the soda, at concentrations of 0.015 to 3.6 mg per kg (Study).
The headliner was 4,4′-methylenedianiline, a primary aromatic amine and suspected human carcinogen, which crossed into the drink at a level exceeding its specific migration limit, the legal ceiling written into EU food-contact rules precisely to keep chemicals like it out of what you swallow (Study). It did not travel alone. The migrants also included UV-curing photoinitiators (among them TPO), the synthetic dye Rhodamine B, and two phthalate plasticizers, the hormone-disrupting family regulators have spent years pulling out of food packaging (Summary). The researchers’ own conclusion was blunt: paper straws are not safer than the plastic ones they were meant to replace (Summary).
Read that again. A cancer-linked chemical left the straw and entered the beverage, over the limit set to protect you. That is not a chemical merely sitting inside the straw; it is one shown to move into what you actually drink.
The conditions were an accelerated stress test, but a hot drink is hardly exotic: a soda left in the sun, a hot cordial, a mulled anything. The straws spanned both plain and printed designs, so this was not one rogue ink run. Nineteen compounds is not a trace whisper; it is a chemistry set, part of which dissolves into your glass.
Forever Chemicals In 90%
Now the finding that made global headlines. Researchers at the University of Antwerp screened 39 straw brands across five materials: paper, bamboo, glass, stainless steel, and plastic (Study). PFAS, the "forever chemicals" prized for repelling water and grease and infamous for never breaking down, showed up almost everywhere except one material. Detection ran 90% in paper straws (18 of 20 brands), 80% in bamboo, 75% in plastic, 40% in glass, and 0% in stainless steel (Report). Across the whole set the team identified 18 distinct PFAS, with the banned legacy compound PFOA the most common, at concentrations up to 7.15 ng/g (Report).
Why are they there at all? PFAS are added to paper to make it shrug off water and grease so the straw does not turn to mush before you finish your drink; the very property that makes them useful is the one that makes them permanent. That PFOA topped the list is its own indictment: the compound has been globally restricted since 2020, yet it is still the forever chemical showing up most often in a product marketed as the responsible choice. And this was no one-lab fluke. A US study nicknamed "The Last Straw" had already tested 43 brands and found PFAS in the paper and other plant-based straws (21 different compounds, 0.043 to 29.1 ng per straw), while the plastic straws contained none (Study). When those researchers steeped the worst-offending brand in water, about two-thirds of its PFAS leached out (Study). Two teams, two continents, same verdict: the "natural" straw is the one soaked in synthetic forever chemicals.
What PFAS Do To You
Why fuss over nanograms? Because PFAS do not leave. Your body cannot break them down, so they accumulate; every exposure stacks onto the last (Opinion). That is exactly why regulators set the bar so brutally low: the European Food Safety Authority’s tolerable weekly intake for the sum of four major PFAS is just 4.4 nanograms per kilogram of body weight, per week, a limit anchored to a reduced immune and vaccine response (Opinion).
The broader health record is not reassuring either. The US EPA links PFAS exposure to weakened immune and vaccine response, higher cholesterol, developmental effects including low birth weight in babies, hormone interference, and some cancers: prostate, kidney, and testicular (Overview). The National Toxicology Program concluded that PFOA and PFOS are "presumed to be an immune hazard to humans" (Assessment), and the ATSDR catalogs the same associations at the population level (Health summary). None of that is a verdict on a single sip. But it is the reason "just a little PFAS in almost every straw" is not something to wave off; the toxicology here is about a lifetime of small additions, not one heroic exposure, and a daily straw is exactly the kind of small, repeated, avoidable addition that adds up.
The Eco-Swap Backfired
Here is the bitterest twist. The entire point of the paper straw was to be the clean, compostable, ocean-friendly choice. It fails on both counts.
On safety, the science is unambiguous: the soda study concluded paper straws are not safer than plastic (Study), and the Antwerp team put it just as plainly: paper straws "may not be better than plastic versions" (Report). To be clear, none of this makes plastic the hero. Plastic straws carried PFAS in 75% of brands too, and they shed microplastics into your drink. The point is narrower and, honestly, worse: the swap bought you nothing. You traded one contaminated straw for another and paid a premium to feel virtuous doing it.
On the environment, the failure is just as complete. PFAS are built around the carbon-fluorine bond, one of the strongest in all of chemistry, which is precisely why they are called forever chemicals. A paper straw laced with them does not cleanly return to soil; the study authors noted that plant-based straws containing PFAS are "not necessarily biodegradable" (Study). So the "compostable" straw does not reliably compost, and it seeds persistent chemicals into whatever it was supposed to enrich. The one thing a paper straw was meant to leave behind (nothing) is the one thing forever chemicals refuse to do.
More Than Just PFAS
PFAS are not even the whole rap sheet, and no, it is not the glue (the adhesive is the boring, clean part of the straw). The real trouble hides in the coating, the resin, and the ink.
Start with chloropropanols. A 2025 analysis found paper straws can carry 3-MCPD (a suspected carcinogen) and 1,3-DCP (a genotoxic Category 1B carcinogen), and traced both to the PAE wet-strength resin, the treatment that stops the straw from dissolving in your drink (Study). Then there are mineral oils. A 2023 study measured the saturated fraction (MOSH) at 1.5 to 51 mg/kg and the more worrying aromatic fraction (MOAH) at 0.05 to 0.59 mg/kg across paper straws, with one straw exceeding both action limits, and found 60% of the straws (12 of 20) carried at least one phthalate (Study). The MOAH fraction is the one to watch, because certain mineral-oil aromatics are flagged for genotoxicity.
In fairness, that same study found no bisphenols and no primary aromatic amines in the particular straws it tested; the exact cocktail varies from brand to brand (Study). But that is not comfort; it is a lottery. You cannot see which toxins your straw drew, or how many, and you are buying a ticket with every drink. Add it up across the studies and the pattern is grim: forever chemicals in most brands, resin carcinogens in some, mineral-oil aromatics and phthalates in others, and a soda test that caught a suspected carcinogen crossing the line. No single straw carries all of it, but "paper straw" has become a wrapper for a rotating menu of things you would never knowingly order.
Why Gamble On It
Now the honest part, because health writing that overstates its hand deserves to be ignored. Three things get blurred that should be kept apart: a chemical present in the straw, a chemical shown to migrate into a drink, and a chemical proven to harm you at the dose a straw delivers.
The migration evidence is real but bounded. The 90%-of-straws PFAS surveys measured what is in the material; they did not measure how much leaches into an actual beverage. The single leaching experiment used plain water on a worst-case brand, and its rough estimate put one straw’s PFOA at around 0.1% of the EPA reference dose (Study), a back-of-envelope figure, not a formal risk assessment. And the carcinogen-in-soda result came from a deliberate stress test: hot (70°C) carbonated liquid for half an hour, not a cold iced coffee (Study). No one has proven that one paper straw will make you sick.
So why not shrug and sip? Because the question runs the wrong way. These straws contain suspected carcinogens and forever chemicals; several of those compounds have been caught leaking into a drink in a hot-soda stress test; and the exact dose in everyday use is simply unmeasured. You can spend years waiting for a precise number, or you can spend nothing and remove the exposure entirely. When the downside is "cancer-linked chemicals that never break down" and the fix is free and reusable, the gamble is not worth taking. Why bet your immune system on a straw?
The Rules Are Changing
Regulators are not waiting for the perfect study either. Under the EU’s new Packaging and Packaging Waste Regulation (EU) 2025/40, PFAS in food-contact packaging face hard limits from 12 August 2026, banned above strict thresholds (Regulation). The same regulatory wave that banned single-use plastic straws (and pushed the market to paper in the first place) is now coming for the forever chemicals in their paper replacements. When the rulebook is being rewritten to get a chemical out of your packaging, that is a fair signal to stop drinking through it.
Frequently Asked Questions
Do paper straws contain PFAS forever chemicals?
Yes, in most brands tested. A University of Antwerp study screened 39 straw brands across five materials and detected PFAS, the so-called forever chemicals, in about 90% of paper straws (18 of 20 brands), versus 0% of stainless steel straws. Across the whole set researchers identified 18 distinct PFAS, with the banned legacy compound PFOA the most common. Report
Are paper straws safer than plastic straws?
Studies suggest they are not. The 2024 soda migration study concluded paper straws are not safer than the plastic ones they were meant to replace, and the Antwerp team said paper straws may not be better than plastic versions. That does not make plastic the hero either, since PFAS turned up in 75% of plastic brands and plastic straws also shed microplastics into your drink.
What chemical leaked out of paper straws into soda?
In a 2024 study, scientists put nine paper straws into a carbonated soft drink held at 70C for 30 minutes and found 19 separate compounds migrated into the liquid. The standout was 4,4′-methylenedianiline, a suspected human carcinogen, which crossed into the drink at a level above its EU legal migration limit. The migrants also included UV-curing photoinitiators, the dye Rhodamine B, and two phthalate plasticizers. Study
What is the safest type of straw to use?
Stainless steel was the clean material: it tested 0% PFAS in both the European and US studies. For that reason the Antwerp study’s senior author, Dr. Thimo Groffen, advised using a stainless steel straw or just avoiding straws altogether. A reusable steel straw has no fluorinated coating, no wet-strength resin, and no printed ink to leak. Glass is a step up from paper but not spotless, with PFAS still found in 40% of glass brands. Report
Are paper straws actually biodegradable and compostable?
Not reliably, when they carry PFAS. These forever chemicals are built around the carbon-fluorine bond, one of the strongest in chemistry, which is exactly why they do not break down. The study authors noted that plant-based straws containing PFAS are not necessarily biodegradable, so a paper straw laced with them does not cleanly return to soil and can seed persistent chemicals into whatever it was meant to enrich.
Key Takeaways
- A suspected carcinogen leaked into soda, over the legal limit. Nine paper straws in hot carbonated drink released 19 compounds, including 4,4′-methylenedianiline above its EU migration limit (Study).
- Forever chemicals hit about 90% of paper straws. PFAS were found in 90% of paper brands (and 0% of stainless steel), spanning 18 distinct compounds (Report).
- PFAS build up and never leave. They accumulate in the body, and EFSA’s tolerable weekly intake is just 4.4 ng/kg (Opinion); PFOA and PFOS are a presumed immune hazard (Assessment).
- The eco-swap backfired. Scientists found paper straws are not safer than plastic (Study), and PFAS-laced ones are not reliably biodegradable either (Study).
- It is not only PFAS. Paper straws can also carry resin-derived carcinogens (3-MCPD, 1,3-DCP) and mineral-oil contaminants (Study).
- Stainless steel was the clean material. It tested 0% PFAS in both the European and US studies: the obvious swap (Study).
Throw Out Your Paper Straws
The bottom line is not complicated: stop using paper straws. They contain suspected carcinogens and forever chemicals, some of which have been caught migrating into a drink under a hot-soda stress test, and they do not even deliver the environmental win they were sold on. The feel-good swap turned out to be neither safe nor green.
The fix costs one purchase and lasts for years. Stainless steel was the only straw material at 0% PFAS in both studies, which is exactly why the Antwerp study’s senior author, Dr. Thimo Groffen, advised people to use a stainless steel straw "or just avoid using straws at all" (Report). A reusable stainless steel straw has no fluorinated coating, no wet-strength resin, and no printed ink to leak; it sidesteps the entire problem in a single move and pays for itself within a week. (Glass is a step up from paper, but it is not spotless: the Antwerp team still found PFAS in 40% of glass brands, versus 0% for steel.) Toss one in a bag, one in a drawer, one in the car, and the daily decision disappears. If you truly need a disposable now and then, that is a separate debate for another day; the point here is singular and firm: get the paper straws out of your drinks.
This is the rare health fix with no catch: nothing to buy monthly, no dose to titrate, no side effects to weigh. You are not gambling on a benefit; you are simply subtracting an exposure that never had to be there. The paper straw was sold as the conscientious choice, and the most conscientious thing you can now do with it is stop putting it in your mouth.
The research on your exact glass is still being written, but the safer choice is already free, reusable, and probably sitting in a drawer. That is worth acting on today.
This article is for educational purposes and is not medical advice. Talk to a qualified clinician before changing your health regimen.
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