A building block of hard plastics and can linings that behaves like a weak oestrogen. Heat and acidity make it leach into food and drink.
Bisphenol A (BPA) is used to make hard, clear polycarbonate plastic and the resin that lines most food and drink cans. It behaves like a weak oestrogen in the body, which is why it has been studied so heavily. As older products are reformulated, BPA is often replaced by close cousins such as BPS and BPF, which look chemically similar and are still being researched.
The main routes are food and drink: the lining of tinned foods and drinks, hard reusable plastic bottles and older food-storage tubs, and, more than most people expect, thermal paper receipts, where BPA or BPS sits loose on the surface and transfers to your fingers. Heat and acidity speed up how much leaches out, so microwaving or storing hot, oily or acidic food in plastic is the situation to avoid.
Because BPA can mimic oestrogen, it is treated as a substance of concern by the Endocrine Society, the US NIEHS and European regulators. In 2023 the European Food Safety Authority sharply lowered the amount it considers tolerable, and the EU has moved to restrict BPA in food-contact materials. Human studies have linked higher levels with effects on fertility, metabolism and child development, though, as with most of these chemicals, this is largely population-level association rather than proof of cause in one person. A fair reading is that reducing a daily, food-based source is sensible, not that a tin of beans is dangerous.
Beyond that: move long-term food storage to glass or stainless steel, use a glass or steel water bottle, and decline printed receipts where you can, or at least wash your hands before eating after handling them. Many canned foods, from sardines to tomatoes, are genuinely nutritious, so the aim is to reduce reliance on packaging chemicals, not to avoid the food inside.
You will not eliminate bisphenols entirely, and you do not need to. Cutting the heated-plastic and daily-can habits removes most of the everyday load. Do the easy swaps and keep the occasional tin firmly in "no big deal" territory.
Sources: Endocrine Society (EDC scientific statements), European Food Safety Authority (2023 BPA reassessment), US NIEHS. Written by M. Videika, The Hormone Blueprint. Educational only, not a substitute for medical advice.