What it is
Code “7” is the catch-all bin — anything not codes 1–6 — but its famous resident is polycarbonate: hard, glass-clear, nearly unbreakable, and polymerised from bisphenol A. Tap it and it rings; drop it and it shrugs. Every polycarbonate item is BPA holding hands in a chain, and some of those hands let go.
Where you meet it
Office water-cooler bottles, older reusable drink bottles, kettle sight-windows, blender and food-processor bowls. BPA-based epoxy also lines most food cans, and BPA’s cousin BPS coats thermal receipts.
What the research shows
The exposure link is unusually direct: in a Harvard crossover trial, students who drank from polycarbonate bottles for one week raised their urinary BPA by 69% (Environmental Health Perspectives, 2009) human trial — a trial of exposure, not of harm.
On harm, the regulators split — and honestly reporting that split matters. EFSA’s 2023 re-evaluation cut the tolerable daily intake ~20,000-fold to 0.2 ng/kg/day, concluding average dietary exposure exceeds it (EFSA) agency, resting mainly on immune effects in animal studies animal plus human observational associations human obs.. The EU then banned BPA in food-contact materials (Regulation 2024/3190, phasing in from 2025). The US FDA and FSANZ still assess BPA as safe at current exposure levels agency. Same evidence, opposite conclusions — an unresolved scientific argument, not a settled fact either way.
What I do
Old polycarbonate bottles are gone — my BPA-plastic protein shaker was an early casualty, replaced with steel. Glass and stainless are the defaults; canned food is occasional rather than daily; receipts stay at the shop.
The honest bit
“BPA-free” is not “bisphenol-free”. The common substitutes BPS and BPF showed hormonal activity comparable to BPA in a systematic review (EHP, 2015) lab animal — a textbook regrettable substitution. Tritan, the flagship BPA-free copolyester, is messier still: independent lab tests reported estrogenic activity in BPA-free plastics (Scientific American, 2014), the manufacturer sued the scientist, a jury sided with the company, and the science remains publicly unresolved early. My conclusion isn’t “Tritan is dangerous” — it’s that I’d rather drink from materials that don’t require a court case to interpret.