Plastics, Packaging, and Cookware

TL;DR. Chemicals migrate from packaging and cookware into food, and heat, fat, and acid all increase it. BPA and phthalates are endocrine active at doses that are genuinely argued about, and the regulatory picture has shifted substantially: EFSA cut its tolerable daily intake for BPA in 2023 by a factor of about twenty thousand, while other agencies disagreed. PFAS are the more serious long-term problem, because they persist essentially forever and are now in nearly everyone's blood. Non-stick pans are safe in normal use and dangerous when overheated empty, mostly to birds. The practical rules are short and worth following.

1. What migrates, and what makes it worse

Migration is the movement of chemicals from packaging or cookware into food. It is normal, regulated, measured, and increased by:

The two rules that follow from that table cover most of the practical advice in this chapter: do not heat food in plastic, and replace scratched or degraded containers and pans.

2. The recycling codes, and which are which

Practical shorthand: 2, 4, and 5 are the safer everyday choices; 3, 6, and 7 are the ones to avoid for hot or fatty food.

3. BPA and its replacements

Bisphenol A is used to make polycarbonate plastic and epoxy resins, including the linings of food and drink cans. It is a weak oestrogen mimic.

Where it is: can linings (the largest dietary source), older polycarbonate bottles and food containers, and thermal paper receipts, which is a substantial dermal exposure route and is rarely mentioned.

The regulatory situation is genuinely divided, and this is instructive:

• EFSA's 2023 re-evaluation cut the tolerable daily intake from 4 µg/kg/day to 0.2 ng/kg/day, a reduction of a factor of roughly 20,000, on the basis of immune system effects (increased Th17 cells) in animal studies. At that TDI, EFSA concluded average European exposure exceeds it.
• The EU has since moved to ban BPA in food contact materials, with phase-in from 2025.
• The US FDA and Germany's BfR disagreed, maintaining that current exposures are safe based on their reading of the same evidence, particularly the large CLARITY-BPA programme, which found effects mainly at high doses.

How to read that: this is a live scientific disagreement about which endpoints and which studies to weight, not a case of one side ignoring evidence. It is a genuine example of precaution being applied differently.

The replacement problem. "BPA-free" products commonly use BPS or BPF, structurally similar bisphenols. Laboratory studies find they have comparable oestrogenic activity, and they are far less studied. "BPA-free" is not a guarantee of anything except the absence of that specific molecule, and it is a good illustration of regrettable substitution, where a regulated substance is replaced by a less-studied relative.

Practical steps: reduce canned food where convenient (fresh, frozen, dried, or carton alternatives), avoid heating food in plastic, do not put polycarbonate in the dishwasher, decline paper receipts or handle them briefly, and replace scratched or cloudy plastic containers.

4. Phthalates

Plasticisers that make PVC flexible, and also solvents and fragrance carriers.

Where they are: food packaging and processing equipment (tubing, conveyor belts, gaskets), cling film (older PVC types), fragranced personal care products, air fresheners, vinyl flooring, and medical tubing.

Why they are a concern: several are anti-androgenic, interfering with testosterone signalling. Animal studies show reproductive tract effects from prenatal exposure. Human epidemiological studies have associated prenatal phthalate exposure with altered anogenital distance in male infants and with neurodevelopmental measures. The human evidence is associational and the mechanism is plausible, and several phthalates (DEHP, DBP, BBP) are restricted in the EU in toys, childcare articles, and some food contact uses.

Dairy and fatty foods carry the highest levels, partly from processing equipment. A widely reported finding is that highly processed foods and fast food are associated with higher phthalate levels than home-cooked equivalents, which is another mechanistic thread in the ultra-processed food story (Chapter 58).

Practical steps: cook from raw ingredients more often, avoid heating in plastic, choose fragrance-free personal care products (fragrance is a common phthalate carrier and is not required to be itemised on labels), ventilate, and avoid vinyl gloves for food handling.

5. PFAS: the more serious problem

Per- and polyfluoroalkyl substances, called "forever chemicals" because the carbon-fluorine bond is among the strongest in organic chemistry and they do not meaningfully degrade in the environment or in the body.

Where they are: non-stick cookware manufacture, grease-resistant food packaging (fast food wrappers, microwave popcorn bags, moulded fibre takeaway bowls), stain-resistant fabrics and carpets, waterproof clothing, firefighting foam, cosmetics, dental floss, and drinking water near contaminated sites.

Why they matter:

• Half-lives in humans of years: roughly 2 to 8 years for PFOA and PFOS depending on the compound and the study.
• Detectable in the blood of essentially the entire population of industrialised countries.
• The C8 Science Panel, an unusually strong study set up as part of a legal settlement covering around 69,000 people exposed via drinking water near a manufacturing plant, found "probable links" with kidney cancer, testicular cancer, ulcerative colitis, thyroid disease, high cholesterol, and pregnancy-induced hypertension.
• Additional associations with reduced vaccine antibody response in children, low birth weight, and liver effects.

The regulatory response has accelerated: the US EPA set enforceable drinking water limits for several PFAS in 2024 at 4 parts per trillion for PFOA and PFOS, which is close to the detection limit. The EU is considering a broad restriction on the whole class. PFOA and PFOS have been phased out of manufacturing, and replacement short-chain PFAS are less studied.

Practical steps: avoid grease-proof takeaway and fast food packaging where you can, avoid microwave popcorn bags (make it in a pan), be cautious with stain-resistant treatments, check whether your water supply publishes PFAS data, and note that reverse osmosis and some activated carbon filters remove PFAS while ordinary jug filters generally do not.

6. Microplastics

Fragments under 5 mm, and nanoplastics below 1 µm, found essentially everywhere: oceans, soil, air, drinking water, food, and human tissue including placenta, blood, and lung.

The 2024 finding using improved detection methods estimated around 240,000 plastic particles per litre in bottled water, mostly nanoplastics, roughly 10 to 100 times previous estimates.

Main dietary sources: bottled water, seafood (especially bivalves eaten whole), tea in plastic mesh bags (which shed billions of particles into a hot cup), salt, and food packaging.

What is known about health effects: very little. Laboratory and animal studies show inflammation, oxidative stress, and effects on the gut barrier at high exposures. Human health effects are not established. A 2024 study finding microplastics in carotid artery plaque associated with higher cardiovascular events attracted enormous attention and is a single observational study.

The honest position: this is a genuine and rapidly developing area of concern, the exposure is universal and rising, and anyone telling you confidently what it does to human health is ahead of the evidence. Reasonable and low-cost responses: drink tap water rather than bottled, avoid plastic tea bags, do not heat food in plastic, and reduce plastic packaging where convenient.

7. Cookware

Non-stick pans, honestly:

• PTFE (Teflon) itself is inert and not absorbed if a flake is swallowed. It passes through.
• PFOA, the processing aid historically used to make it, was the problem, and it has been phased out of manufacture since around 2013 in the US and EU.
• Overheating is the genuine hazard. Above roughly 260 °C the coating begins to degrade, and above 350 °C it releases fumes causing polymer fume fever, a transient flu-like illness in humans. It is rapidly lethal to pet birds, whose respiratory systems are exquisitely sensitive. Every year there are cases of birds dying from an overheated pan in the same house.
• Never preheat an empty non-stick pan, which is how it reaches those temperatures within a couple of minutes.
• Replace scratched or flaking pans, not because the flakes are toxic but because the coating is no longer intact and the underlying surface is exposed.

Aluminium foil in contact with acidic or salty food at high heat does transfer measurable aluminium. Ordinary use is not a demonstrated health concern; using baking parchment for acidic dishes is a simple alternative.

8. The practical rules

The whole chapter reduces to a short list:

1. Do not heat food in plastic. Transfer to glass or ceramic before microwaving. This is the single highest-value rule.
2. Do not put hot food into plastic containers. Let it cool first.
3. Replace scratched, cloudy, or warped plastic containers and non-stick pans.
4. Do not put plastic in the dishwasher if you can avoid it; the heat and detergent accelerate degradation.
5. Never preheat an empty non-stick pan, and keep birds out of the kitchen.
6. Prefer glass, stainless steel, and ceramic for storage and cooking.
7. Drink tap water rather than bottled, where the supply is safe.
8. Reduce canned food somewhat, and avoid greaseproof fast-food packaging.
9. Avoid plastic mesh tea bags.
10. Cook from raw ingredients more often. It addresses phthalates, PFAS packaging, sodium, and ultra-processing simultaneously, which is a recurring theme in this book.

9. The bottom line

• Migration from packaging and cookware is real, regulated, and driven mainly by heat, fat, acid, time, and damage. Not heating food in plastic addresses most of it.
• BPA regulation is genuinely divided: EFSA cut its tolerable intake by a factor of about 20,000 and the EU is banning it in food contact, while the FDA maintains current exposures are safe. "BPA-free" often means BPS or BPF, which are less studied and structurally similar.
• Phthalates are anti-androgenic in animal studies, are highest in processed and fast food, and hide in "fragrance" on cosmetic labels.
• PFAS are the more serious long-term problem: half-lives of years, near-universal blood levels, and probable links to kidney and testicular cancer, thyroid disease, and raised cholesterol from the C8 study.
• Microplastics are everywhere, exposure is rising, and human health effects are genuinely not established. Low-cost responses are reasonable; confident claims in either direction are not.
• Non-stick pans are safe in normal use, dangerous when preheated empty, and lethal to pet birds when overheated. Stainless steel, cast iron, and glass are the safest defaults.

Sources and notes

Migration principles and food contact material regulation follow EU Regulation 1935/2004 and FDA food contact substance rules. BPA's endocrine activity and the divergent regulatory positions follow EFSA's 2023 re-evaluation, which reduced the tolerable daily intake to 0.2 ng/kg/day, the EU restriction that followed, and the contrary assessments from the FDA and Germany's BfR; the CLARITY-BPA programme is published by the NTP and FDA. Bisphenol substitutes BPS and BPF and their comparable in vitro activity follow Rochester and Bolden, Environmental Health Perspectives, 2015. Phthalate anti-androgenic effects follow Swan's work on anogenital distance and the NTP-CERHR reviews; higher levels with fast food follow Zota et al., Environmental Health Perspectives, 2016. PFAS persistence, human half-lives, and near-universal blood detection follow ATSDR and CDC NHANES data; the health links follow the C8 Science Panel's probable-link findings; the 2024 EPA drinking water limits are published by EPA. Microplastic and nanoplastic counts in bottled water follow Qian et al., PNAS, 2024; the carotid plaque association is Marfella et al., NEJM, 2024, a single observational study. PTFE inertness, polymer fume fever, and avian mortality follow toxicology and veterinary literature; PFOA phase-out follows the EPA stewardship programme. Aluminium and Alzheimer's disease has been reviewed repeatedly without support, summarised by the Alzheimer's Society. Cast iron increasing dietary iron follows published cooking studies.

Open questions. What microplastic exposure does to human health is essentially unknown, and confident claims in either direction outrun the evidence. BPA is the clearest current example of expert bodies reaching opposite conclusions from the same dataset.

👉 Next: what your skin absorbs.