Polycarbonate (PC)

Polycarbonate is the hard, glass-clear, nearly unbreakable plastic that was everywhere a generation ago — baby bottles, sports bottles, water-cooler jugs. Its defining fact: it's made by chemically linking BPA (bisphenol A) molecules into long chains. Most of the BPA reacts into the polymer, but small unreacted amounts remain and can migrate into food and drink. When you hear "the BPA plastic," this is the material people mean.

Because almost nothing else is this clear, this tough, and this heat-tolerant at once. Polycarbonate looks like glass but survives being dropped, which made it the obvious choice for baby bottles, reusable drink bottles, blender jars, eyewear, and safety glazing. Those genuinely useful properties are why it spread so widely — and why, once the BPA evidence accumulated, replacing it in food roles took regulation and a decade of reformulation.

PC, polycarbonate, or trade names like Lexan and Makrolon. On resin codes it hides in 7 — the "other" catch-all — though not everything marked 7 is polycarbonate. Often there's no marking at all, so the practical tell is the material itself: rigid, transparent, glassy-looking plastic that doesn't flex, especially on items bought before roughly 2012. "BPA-free" labels exist largely as a response to this plastic.

Mostly in older or behind-the-scenes items: pre-2012 baby bottles and sippy cups, old hard clear sports bottles, the big blue jugs on office water coolers, viewing windows and jugs on some kettles, blender and food-processor jars, light fittings, safety glasses, and CDs. New baby bottles and most new drink bottles have moved to other materials, so the question is usually what's lingering in your cupboards.

Through food and drink contact. Trace unreacted BPA in the plastic migrates into contents, and migration climbs with heat (hot liquids, dishwashers, boiling), with age, and with surface wear — a scratched, clouded ten-year-old bottle releases more than a new one. This is why heated polycarbonate baby bottles were the central worry, and why old hard clear bottles are the items most worth retiring today.

BPA is one of the most-studied hormone-active chemicals: it can weakly mimic oestrogen, and research has associated higher exposure with effects on fertility and on the developing baby, which is why pregnancy guidance often mentions it. The encouraging part is that polycarbonate is now an easy exposure to cut — it's a short list of identifiable items. During pregnancy, swap any old hard clear bottle for glass or stainless and you've addressed the main household source.

Research has associated higher BPA levels with lower sperm quality and altered hormone levels in men, though human findings are mixed and mostly observational — they show links rather than settled cause and effect. For couples trying to conceive, the cost-benefit is straightforward: retiring an old polycarbonate bottle costs nothing, and it removes one of the better-documented hormone-active exposures while the science continues to firm up.

Babies were the reason this material's story changed. Heated bottles plus small bodies plus developmental sensitivity made infant BPA exposure the priority concern, and regulators acted — the EU restricted BPA baby bottles in 2011 and the US in 2012. New baby bottles are not polycarbonate. The remaining watch-out is hand-me-downs: hard clear bottles or sippy cups from an older sibling or relative may pre-date the change. When in doubt, replace.

Older adults aren't a specific focus of BPA research — the developmental windows of pregnancy and early childhood are where the evidence concentrates. The same easy steps apply at any age, particularly retiring aged polycarbonate items, since older plastic releases more.

That BPA migrates from polycarbonate into food and drink, more with heat and age — this is well measured. That BPA is hormone-active at low doses in laboratory studies, with human studies linking exposure to reproductive and developmental outcomes. And that regulators have steadily tightened: baby-bottle bans in 2011–2012, then EFSA's 2023 re-evaluation cutting its tolerable intake roughly 20,000-fold, followed by a broad EU ban on BPA in food-contact materials. The direction of regulatory travel has been one way.

Today, modest for most households — simply because polycarbonate has already left most food roles. If your bottles and baby items were bought new in recent years, you likely have little of it in food contact. The meaningful remaining exposure is concentrated in specific items: an old hard clear bottle still in daily use, hand-me-down feeding gear, or hot drinks from a polycarbonate vessel. Those are worth acting on; the rest is housekeeping.

Glass and stainless steel are the clean answers for bottles, jugs, and storage — no bisphenols of any kind. Among plastics, polypropylene and Tritan-type copolyesters replaced polycarbonate in most products. One honest caveat: "BPA-free" hard plastic often uses BPS or BPF, close chemical cousins with similar hormone-like activity in studies. So treat BPA-free as better-than-before rather than problem-solved, and reach for glass or stainless when you want certainty.

Easy — easier than almost any material in this section, because the work is mostly identifying a handful of legacy items rather than changing habits. One cupboard audit finds them: hard, clear, rigid, glassy-looking, usually years old. Non-food polycarbonate (light fittings, glasses, appliance housings) doesn't need attention — migration into food and drink is the route that matters, and that's a short list.

Do a two-minute cupboard check: pull out any hard, clear, rigid plastic bottle, cup, or baby item that's more than a few years old or has no marking. If it's glassy-stiff rather than flexible, retire it from food and drink duty — recycle it or demote it to holding pens. Replace with glass or stainless and the job is done for good.

Polycarbonate is largely a solved problem for new purchases — the system already moved. Your job is the leftovers: old bottles, hand-me-down baby gear, and hot-drink contact with hard clear plastic. Clear those, choose glass or stainless where you want certainty, and keep healthy scepticism about "BPA-free" hard plastics, since the substitutes are close relatives. That's the whole assignment.

FDA's BPA pages, NIEHS's bisphenol research summaries, EFSA's 2023 BPA re-evaluation, and the regulatory history of baby-bottle restrictions. See References below.