What it is
Nylon — polyamide, in the datasheets — was the first fully synthetic fibre (1935): strong, slick and heat-tolerant enough to sit in your roasting pan. It has no resin code of its own; moulded nylon lands in the “7 — other” bin, which is one reason it flies under the radar.
Where you meet it
“Silken” pyramid teabags, kitchen utensils (many black spatulas and slotted spoons), oven and slow-cooker bags, toothbrush bristles, tights and activewear, carpet.
What the research shows
Nylon keeps turning up at the top of shedding measurements lab:
- The famous one: a single nylon/PET “silken” teabag at brewing temperature released ~11.6 billion microplastics plus ~3.1 billion nanoplastics into one cup (McGill, ES&T, 2019). A published technical comment challenged the counting method early — nano-counting is hard, and I’d rather tell you that than pretend the number is carved in stone. The follow-up by a different group still measured nylon-6 teabags at ~8.2 million particles/mL (Chemosphere, 2024).
- NIST found food-grade nylon oven/slow-cooker bags shed ~7× more nanoparticles than plastic-lined coffee cups (ES&T, 2022).
- Germany’s BfR measured polyamide oligomers migrating from some nylon utensils above its guidance value and advised keeping nylon’s contact with hot food “as brief as possible” (BfR, 2019) agency, based on animal data animal.
- The kicker: in Columbia’s bottled-water study, the single most abundant polymer wasn’t the PET bottle — it was polyamide, probably shed by the purification filters (PNAS, 2024).
What I do
Loose-leaf tea through a steel strainer. Utensils are steel and wood — and nothing plastic rests in a simmering pot, which is where the BfR migration scenario lives. Nylon oven bags I simply skip; a lidded roasting dish does the same job.
The honest bit
There’s no human outcome data specific to nylon — the teabag particles harmed water fleas animal, and the oligomer guidance is precautionary. Nylon in your leggings is a textile-shedding question, not a hot-food one. The pattern that earns nylon its page is simpler: wherever fine nylon structures meet hot water, the particle counts come back enormous.