Every material gives something to your food.
What is Migration?
When food sits in a container, molecules from the container surface transfer into the food. This is called migration. It happens with every material — glass, plastic, silicone, steel, ceramic.
The question isn't whether migration occurs. The question is: what migrates, how much, and does it matter?
In the UK and EU, food contact materials are governed by EC 1935/2004, which requires that materials must not transfer their constituents to food in quantities that could endanger health.
What 304 stainless steel releases.
304 stainless steel contains chromium and nickel. Under certain conditions, trace amounts of these metals can migrate into food:
- At fridge temperature (cold storage) Migration is effectively zero. The amount of nickel that transfers to food during cold storage is below the natural nickel content already present in the food itself. For context: 100g of cashew nuts contains more nickel than a year's worth of cold storage in a steel container.
- At cooking temperature with neutral foods (pH > 5) Very low migration. Well within regulatory limits. This covers ~70-80% of meals — rice, pasta, meat, vegetables, most soups.
- At cooking temperature with acidic foods (pH < 5) This is the condition people worry about — so we had it tested. Our containers are independently migration-tested under hot, acidic conditions: none detected. The full SGS report is published on this site.
Our recommendation: Store anything at any temperature. Reheat and cook on the hob or in the oven — that's where this material shines.
The difference that matters.
There's a fundamental difference between what stainless steel releases and what plastic or silicone releases.
Stainless steel releases natural elements.
Nickel and chromium are elements — they exist in soil, water, and food naturally. The nickel ion (Ni2+) released from steel is the same ion you get from eating spinach, chocolate, or nuts. Your body has evolved to process these elements in small quantities.
Plastic and silicone release synthetic compounds.
Microplastics, bisphenols, phthalates, and cyclic siloxanes are synthetic — manufactured molecules with no natural equivalent. Your body has no evolved mechanism for processing them. Some are classified as endocrine disruptors.
What "stainless steel container" actually means on the market.
Search for "stainless steel food container" on Amazon. Almost all of them are stainless steel bodies with:
- Silicone gasket seals in the lid
- Plastic locking mechanisms
- Glass lids with silicone trim
- Non-stick coatings on the interior
The body is steel. But the part that touches your food most intimately — the seal, the lid surface — is silicone or plastic. Our containers have no silicone anywhere. The lid is 304 stainless steel — a mechanical friction fit, no gasket, just steel on steel. Laid flat it stays securely sealed; not fully airtight, so not for carrying liquids loose in a bag — but nothing synthetic ever touches your food.
Don't take our word for it.
We commission independent testing under our company name — Palm & Pine Living Limited.
- SGS Migration Test: Metal release into standardised food simulants at specified temperatures and durations.
- SGS Chemical Composition Analysis: Elemental composition analysis on the stainless steel food container sample, confirming compliance with BS EN 10088-1:2014 type X5CrNi18-10 / 304 composition.
Both reports are available on our Full Disclosure page.