Is stainless steel cookware safe?

Stainless steel is iron alloyed with chromium — the chromium is what forms the passive oxide layer that makes it "stainless" — plus nickel in the grades used for cookware. 304 and 18/10 are overlapping descriptions of the same kind of steel: roughly 18% chromium and 8 to 10% nickel.

Good cookware is clad: a layer of aluminum (or several) bonded between stainless skins so heat spreads sideways instead of pooling over the burner. That construction is what separates a pan that cooks evenly from one that scorches in a ring, and it is unrelated to safety.

Three honest readings. The effect is real and was measured in a peer-reviewed journal, not inferred. The quantities are micrograms from a long acidic cook. And the effect shrinks as a pan ages, which means the worst case is a brand-new pan simmering tomato sauce all afternoon.

Separately, research on stainless utensils exposed to citric, tartaric and lactic acids found that leaching depends largely on the availability of free organic-acid anions to complex the metal ions — which is the mechanism behind why acid, specifically, is what drives this.

• People with diagnosed nickel sensitivity or allergy. This is the group for whom the finding is practically relevant; enameled cast iron is the direct substitute for long acidic cooking.
• Anyone who simmers tomato sauce for hours in a new stainless pot, where you can simply use enamel or glass instead.
• Everyone else: the numbers are small against dietary nickel generally, which comes mostly from food itself — nuts, legumes, chocolate, whole grains.

There is no practical upper temperature. Stainless does not have a coating to degrade, and domestic cooking cannot damage the metal. What it does instead is discolor: the rainbow tinting people worry about is a thin oxide layer from heat and is cosmetic, and the white chalky spots are mineral deposits from hard water, removable with vinegar.

The genuine failure modes are mechanical: a warped base from thermal shock (never run cold water into a screaming-hot pan), and delamination at the bonded base on cheap disc-bottom pans, which is a construction defect rather than a material one.

1. Preheat on medium until a water droplet skitters, then add fat, then food. This is the entire technique for stopping food sticking.
2. Deglaze while hot. Liquid lifts the browned layer in seconds and cleans the pan at the same time.
3. Use baking soda or a stainless scrubber on burnt-on residue. There is no coating to protect, so be as aggressive as you like.
4. Vinegar for mineral spots, never for a long soak on the exterior if the pan has an aluminum-exposed rim.
5. Do not shock it. Let a hot pan cool before it meets cold water, or it will warp.

Two clad stainless options at different price points, plus the enamel alternative for anyone whose main cooking is acidic.