The short version
- Heat, fat and time are what move chemicals out of packaging and into food. One rule covers most of this topic: do not heat food in plastic. Everything else is refinement.
- What is on the front of the pack is marketing. What is on the back is regulated. If a claim appears only on the front, it usually means nothing.
- The brand rankings here are judgements, not measurements. They apply ten stated criteria consistently, and the criteria are published so you can disagree with the reasoning rather than only with the score.
- UK and EU rules diverged in January 2025, and the clearest example is BPA. A tin bought in the UK is not covered by the EU ban.
- Most of this matters less than what you eat. A perfectly sourced ultra-processed diet is still an ultra-processed diet. This topic answers which one do I buy, not what should I eat.
What this section is for
Standing in a supermarket, the question is rarely "is this food healthy". It is "which of these eight near-identical products should go in the basket". That is a different question, it has better and worse answers, and very little published on it is written by anyone without something to sell.
So this topic ranks 256 UK brands against ten stated criteria, picks products across twelve categories, grades 58 everyday situations that put plastic into food, and ranks eight retailers. It is searchable and filterable, it works with no further requests once the page has loaded — which matters, because the use case is standing in a shop — and none of it carries an affiliate link.
One rule does most of the work
Chemical migration out of packaging is driven by three things, and they multiply rather than add.
Heat
The single largest factor. A microwave, a dishwasher cycle, a hot car, or hot food going straight into a container all increase migration substantially over the same plastic sitting at room temperature.
Fat
Most of the compounds involved are fat-soluble, so oily and fatty foods pull more out of packaging than watery ones. Cheese, meat, oils and sauces are where it matters. A bag of dried pasta is not worth a second thought.
Time
Contact duration, including the months before you bought it. A tin stored for a year has had a year of contact; the same food eaten from a carton this week has not.
And damage
Scratched, cloudy or crazed plastic has far more surface area and a degraded barrier. An old scratched container is a worse choice than a new one made of exactly the same plastic.
Which is why do not heat food in plastic captures most of the available benefit in a single habit. It costs nothing, requires no product research, and applies in every kitchen regardless of what is in the cupboard.
BPA: what changed, and why the UK is different
This is the clearest current illustration of why "it is on sale" and "it has been judged safe" are not the same statement.
In April 2023 the European Food Safety Authority re-evaluated bisphenol A and cut its tolerable daily intake from 4 micrograms per kilogram of body weight per day to 0.2 nanograms — a reduction of roughly 20,000-fold, on the basis of effects on the immune system. On EFSA's own figures, typical European dietary exposure then exceeded the new limit by orders of magnitude in every age group. The European Commission banned BPA in food contact materials from 20 January 2025, with phase-out periods running into 2028 for some categories.
The UK did not follow. The Committee on Toxicity considered the same opinion and did not adopt the new tolerable daily intake, noting that the European Medicines Agency and Germany's federal risk assessment institute had both filed diverging views, and that in the Committee's judgement the weight-of-evidence analysis was lacking. The UK position therefore remains the earlier one, and the EU ban does not apply to products made for the UK market.
The three swaps worth making first
Stop heating food in plastic
Decant into ceramic or glass before microwaving, and let food cool before it goes into a plastic container. Highest value, lowest cost, and it needs no shopping decisions at all.
Move tinned tomatoes to glass or carton
Tomatoes are acidic and usually stored a long time, which is close to a worst case for migration from a can lining. One product, one aisle, and the alternatives cost much the same.
Pick one category and upgrade it properly
Trying to optimise an entire shop at once reliably fails. Choose the category you buy most often, spend ten minutes with the aisle-by-aisle picks, and then leave it decided. Do another next month if you feel like it.
Reading a label in fifteen seconds
- Ignore the front on a first pass. "Natural", "farm fresh", "artisan" and most package imagery are unregulated. Terms with legal definitions — organic, free-range, protected designation of origin, certified gluten-free — are the exceptions, and they are usually printed small.
- Read the ingredients list, and count it. It is ordered by weight. A short list of recognisable things is a decent proxy for much of what this topic measures.
- Notice what the front-of-pack claim is doing. "No added sugar" is compatible with a great deal of sugar. "Reduced fat" is relative to the original product, not to anything sensible.
- Look at the packaging as well as the contents — tin, carton, glass or plastic, and whether you intend to heat it.
Keeping this in proportion
- The exposures in this topic are real and worth reducing where reducing them is easy. On the evidence they are not comparable in scale to smoking, blood pressure, or the overall pattern of what you eat.
- If a change here would cost real money, real time or real enjoyment, it is probably not worth making. The good swaps in this topic are the ones that are nearly free.
- Anxiety about food carries its own cost, and someone who ends up frightened of their own kitchen has not come out ahead. Make the cheap changes, then stop thinking about it.
- Where the evidence is genuinely weak, these pages say so rather than rounding up to a warning. Several items are graded Emerging, which means interesting rather than urgent.