What it is
Stainless steel is an alloy of iron, chromium (at least 10.5%), and often nickel. Chromium forms a passive oxide layer that resists rust and staining.
The '18/10' and '18/8' shorthand refers to 18% chromium and 10% or 8% nickel — the two grades most trusted for cookware and food storage.
Why it matters
It is inert with almost all foods, does not require seasoning, and lasts decades with basic care.
Multi-ply construction (tri-ply, five-ply) sandwiches an aluminium or copper core between stainless layers for even heat distribution.
Cheap stainless (200 series, chrome-only) can be less corrosion-resistant and is worth avoiding for cookware.
Common uses
- Cookware — fry pans, sauté pans, stockpots, mixing bowls
- Bakeware — sheet pans, roasting pans, loaf pans
- Storage — water bottles, food containers, thermal flasks
- Small tools — kettles, cutlery, French presses
Safety considerations
- Nickel can leach in very small amounts, especially with highly acidic foods held for hours; this is a real consideration for the small subset of people with confirmed nickel allergy.
- For everyone else, 18/10 stainless is one of the safest food-contact materials available.
- Discoloured 'rainbow' staining is oxidation from overheating, not a safety issue — a paste of baking soda usually restores the surface.
Where you meet it in the home
- Kitchen — cookware, bakeware, sinks, small appliances
- Hydration — bottles, tumblers, coffee flasks
- Baby — bottles, cups, lunch containers
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Frequently asked questions
Is 18/10 stainless steel non-toxic?
Yes. 18/10 stainless is considered one of the safest and most inert cookware materials available for everyday cooking.
Does stainless leach nickel?
Trace amounts, especially with acidic foods cooked for long periods. For most people the exposure is negligible; those with confirmed nickel allergy may prefer cast iron or glass.
Editorial references
- ASTM International — A240 stainless steel grades
- European Food Safety Authority — Metals in food contact materials
Last updated 2026-07-18.