5 Things I'll Never Touch Again — and what the studies actually say

Here's the full breakdown:

1. 1. Paper coffee cups

   They aren't paper. The inside is lined with a thin plastic film — polyethylene — because paper alone would go soggy. Hot liquid degrades that lining. Researchers at IIT Kharagpur poured water at 85–90°C into disposable cups and let it sit for 15 minutes. One cup released roughly 25,000 micron-sized microplastic particles per 100 mL, plus about 102 million sub-micron particles per mL.[1] The degrading lining also shed fluoride, chloride, sulfate and nitrate ions, along with traces of lead, chromium and cadmium.[1] A 2024 follow-up found phthalates and endocrine disruptors including styrene released within minutes at the same temperature.[2] At three hot drinks a day, that's about 75,000 particles.

   What I do:

   Stainless steel or glass. If I'm stuck with a paper cup, I drink it fast — most of the release happens while it sits.

2. 2. Gum

   "Gum base" is a legal umbrella term. Underneath it, most conventional gum uses synthetic polymers — polyethylene, polyvinyl acetate, polystyrene, styrene-butadiene rubber. All permitted by the FDA, none of them listed by name. A UCLA team tested ten brands and presented the results at the American Chemical Society's 2025 spring meeting. On average, 100 microplastic particles were released per gram of gum chewed, with some brands hitting 600. A large piece can shed over 3,000 particles — and 94% of that comes off in the first eight minutes.[3] One detail worth knowing before you go shopping: the same study tested five natural, chicle-based gums alongside the five synthetic ones, and they released similar amounts of microplastics.[4] The researchers suspect contamination introduced during manufacturing rather than the plant base itself. So natural gum gets you out of chewing petroleum-derived polymer, but it isn't the clean fix it looks like.

   What I do:

   Mints.

3. 3. Aerosol dry shampoo

   Benzene is not an ingredient in dry shampoo. It's a contaminant, and it comes from the propellant — butane, isobutane, propane. In 2022, the independent lab Valisure tested 34 dry shampoo brands and found benzene above acceptable levels in nearly 70% of samples. Three lots from one brand exceeded 100 ppm — more than ten times the FDA's conditional limit for drugs.[5] Unilever voluntarily recalled Dove, Nexxus, Suave, TRESemmé and TIGI dry shampoos that October, citing the propellant as the source.[6] Benzene is a classified human carcinogen linked to leukemia and bone marrow cancers.[6] What concerns me most isn't the scalp — it's that you're spraying an aerosol in a small bathroom and breathing it. Valisure sampled the air and found benzene lingering after use.[5] The recalled products were made before October 2021, and the industry has since worked on propellant sourcing. But this is a contamination pathway specific to the aerosol format, and I don't have a way to verify any given can.

   What I do:

   Skip the format. A glycolic acid toner on the scalp handles oiliness for me.

4. 4. Dryer sheets

   That "clean laundry" smell is fragrance chemistry, and you don't get to know what's in it. Neither the FDA nor the CPSC requires individual fragrance ingredients to be disclosed on a label.[8] Anne Steinemann's team at the University of Washington sampled air vented from residential dryers during use of scented detergent and dryer sheets. They found 29 volatile organic compounds, seven of which the EPA classifies as hazardous air pollutants — including acetaldehyde and benzene.[7] Emissions also include terpenes like limonene, which act as primary indoor air pollutants and react with other compounds to form secondary ones.[7] In survey data from the same group, 12.5% of the US population and 28.9% of people with asthma reported health problems from scented laundry products coming off a dryer vent.[7]

   What I do:

   Wool dryer balls or nothing at all. The swap costs nothing and removes an undisclosed ingredient list from my sheets and pillowcases.

5. 5. Receipts

   Thermal receipt paper works by chemistry, not ink. The coating contains a reactive dye and a color developer — usually bisphenol A or bisphenol S — that darkens under the printer's heat.[9] The critical detail: that bisphenol is free, not bound into a polymer. It's sitting loose on the surface, which is why it transfers to skin on contact. Multiple independent studies confirm both the transfer and the absorption, and most of what's absorbed through skin isn't metabolized on the way in — it goes straight into systemic circulation, bypassing the liver.[10] The finding that changed how I handle receipts: in a 2014 PLOS One study, people who used hand sanitizer immediately before holding a receipt absorbed dramatically more. Bisphenol transferred to their hands, then to food they ate, producing a serum spike within 90 minutes. Penetration enhancers found in sanitizers and skincare can increase dermal absorption of compounds like BPA up to a hundredfold.[11] Damp or greasy hands alone raise it about tenfold.[9] So: sanitizer, then receipt, then eating with your hands is close to the worst-case sequence — and it's an extremely normal thing to do. The EU restricted BPA in thermal paper as of January 2020. The US didn't, and BPS, the most common replacement, has similar endocrine activity.[9] "BPA-free" isn't the reassurance it sounds like.

   What I do:

   Digital receipt where it's offered. Or, if you don’t need it, just toss.