Georden Jones, Founder, The Peer Review · Last updated: August 9, 2026
The Short Answer
Stainless steel is a safe, durable, and stable choice for cookware, bottles, and food storage for the large majority of people — which is why it is one of the two “just use this” materials (with glass) across our toxins coverage. It is not perfectly inert, though: it can release small amounts of nickel and chromium into food, most noticeably from new pans and when cooking acidic foods for a long time [1]. For most people those amounts are well below levels of health concern, and the chromium involved is the harmless nutritional form, not the toxic kind [1]. The one group that should pay attention is people with a nickel allergy or systemic nickel allergy syndrome, for whom dietary nickel can be a real trigger [3][4]. The good news: leaching drops sharply once cookware is broken in, so buying quality steel and giving new pans a few uses handles most of it [1].
Quick Answer — is stainless steel safe?
- For most people: yes — a stable, durable default; migrated nickel/chromium sits below health-concern levels [1].
- The catch: new pans and long acidic cooks leach more nickel and chromium; leaching falls after about six uses as the surface matures [1].
- Who should care: people with nickel allergy / systemic nickel allergy syndrome [3][4].
- Best picks: quality graded steel — 18/8, 18/10, 304, or 316/316L; avoid unmarked cheap steel.
- Evidence Rating: General Consensus. Stainless is widely accepted as safe for normal use, with a well-documented, small caveat around nickel for sensitive people and new/acidic cooking [1][5].
Table of Contents
- Why Stainless Steel Is a “Safer” Material
- Where Stainless Steel Shows Up (and the Grades)
- How It Interacts With Your Body
- The Honest Catch: Nickel, New Pans, and Acid
- Who Should Really Worry: Nickel Allergy
- How to Choose and Use Stainless Steel
- FAQ
- The Bottom Line
- References
Why Stainless Steel Is a “Safer” Material
Stainless steel is an alloy — mostly iron, with chromium and usually nickel — and its safety comes from a clever bit of chemistry. The chromium reacts with oxygen to form a thin, self-repairing “passive” layer on the surface that resists corrosion and largely keeps the metal locked in place [1]. That stability is why stainless resists rust, tolerates heat, and does not need a non-stick coating that can wear off. It is durable and inert enough to be a sensible default, in the same “stable material, low exposure” sense that runs through this materials series.
“Inert enough” is the honest phrasing, though. Unlike glass, stainless is not completely non-reactive — the passive layer can give up trace metal ions under the right conditions, which is the caveat the rest of this page is about. As always, the question is not whether any migration happens, but whether the amount reaches a level that matters (Hazard vs. Risk).
Where Stainless Steel Shows Up (and the Grades)
Stainless is everywhere food is: pots and pans, kettles, water bottles, travel mugs, cutlery, mixing bowls, food-storage containers, sinks, and countertops. For food use, the grade is the thing worth knowing:
- 304 (also marked 18/8 or 18/10). The standard food-grade stainless: about 18% chromium and 8–10% nickel. The nickel is part of what makes it corrosion-resistant and non-reactive. This is what most quality cookware and bottles are made of.
- 316 / 316L. Adds 2–3% molybdenum, which improves resistance to acids and salt. Often called “surgical” or “marine” grade; more corrosion-resistant, though not automatically lower-leaching in every test [1][2].
- Unmarked or very cheap stainless. The category to be cautious with — inconsistent alloy quality can mean a weaker passive layer and more leaching.
“18/8” and “18/10” simply describe the chromium/nickel percentages; both are reputable food grades. The number to avoid is no number at all.
How It Interacts With Your Body
The exposure pathway is straightforward: under heat and especially acid, the passive surface layer can release small quantities of nickel and chromium ions into food, which are then eaten [1]. Three things increase it — a new pan whose passive layer has not fully matured, a long cook time, and an acidic food like tomato sauce, citrus, or vinegar. In a well-known Oregon State University study, simmering tomato sauce for six hours raised nickel up to roughly 26-fold and chromium up to 7-fold compared with a control, with the most leaching from new cookware [1].
Two facts keep this in perspective. First, the measured amounts were small — nickel around 0.01–0.21 mg/L, below the levels of health concern for the general population [1]. Second, the chromium released is chromium(III), the form your body uses in trace amounts as a nutrient — not chromium(VI), the toxic, carcinogenic form associated with industrial pollution (Heavy Metals). And crucially, leaching falls sharply with use: the same study found it dropped substantially after about six cooking cycles as the surface stabilised [1]. So the highest-exposure scenario — a brand-new pan simmering acidic sauce for hours — is also the easiest to age out of.
The Honest Catch: Nickel, New Pans, and Acid
Safer material, not perfect material — here is the specific, evidence-based catch:
- New pans leach the most. The passive layer needs a few uses to fully form, so a brand-new pot releases more nickel and chromium than a broken-in one [1]. Washing before first use and simply cooking with it a handful of times reduces this.
- Acid plus long cook times is the worst case. Simmering very acidic foods (tomato, citrus, vinegar-based dishes) for hours pulls out the most metal — especially in a new pan [1]. An occasional acidic dish is a non-issue; daily hours-long acidic simmering in new cookware is the scenario to moderate.
- Quality matters. Reputable graded steel (304, 316/316L, 18/8, 18/10) has a reliable passive layer; unmarked bargain steel is less predictable.
- Damage is minor for most. Scratches from normal use do not turn a safe pan into a hazard for the general population [1][3].
For the average person, the takeaway is reassuring: buy decent steel, break new pans in, and cook normally.
Who Should Really Worry: Nickel Allergy
The one group with a real reason to think about this is people who are nickel-allergic, and especially those with systemic nickel allergy syndrome (SNAS) — a condition in which ingested (dietary) nickel, not just skin contact, can trigger symptoms such as systemic contact dermatitis [3]. For these individuals, cumulative dietary nickel matters, and cookware can be one contributing source.
The clinical guidance here is mixed, so we will give it straight. Some advice for nickel-sensitive people recommends avoiding stainless steel specifically when cooking acidic foods [4]. Other guidance, including from the Nickel Institute, states that provided care instructions are followed, even scratched stainless cookware should not present a problem for people with systemic nickel allergy syndrome [3]. The reasonable reading: if you are nickel-allergic, this is worth a conversation with your dermatologist, and reasonable steps include using well-seasoned (not brand-new) pans, limiting long acidic cooks in stainless, and considering enamelled cast iron or glass for those dishes. A low-nickel diet should only be undertaken under medical supervision [3]. For everyone without nickel sensitivity, this section simply does not apply.
How to Choose and Use Stainless Steel
- Buy graded steel. Look for 304, 316/316L, 18/8, or 18/10. Skip unmarked, suspiciously cheap cookware.
- Break in new pans. Wash before first use and cook with them a few times; leaching drops markedly after roughly six uses [1].
- Don’t do long acidic simmers in brand-new pans. Save the hours-long tomato sauce for a broken-in pot, or use enamelled cast iron or glass for it.
- Care for the surface. Follow manufacturer cleaning guidance; avoid harsh abrasives that needlessly wear the passive layer.
- Nickel-allergic? Personalise it. Talk to your dermatologist, favour seasoned pans, and consider alternative materials for frequent acidic cooking [3][4].
FAQ
Does stainless steel leach into food?
In small amounts, yes — mainly nickel and chromium, and mostly from new pans cooking acidic food for a long time. The quantities are below health-concern levels for most people, and leaching drops sharply after the first several uses [1].
Is the chromium in stainless steel dangerous?
No — the chromium that migrates is chromium(III), a form the body uses as a trace nutrient, not the toxic chromium(VI) linked to industrial exposure [1].
What grade of stainless steel is safest for cooking?
Reputable food grades — 304 (18/8 or 18/10) and 316/316L — all have a reliable corrosion-resistant surface. 316L resists acids and salt best thanks to added molybdenum. The main thing to avoid is unmarked, low-quality steel [2].
Should people with a nickel allergy avoid stainless steel?
It depends and is worth discussing with a dermatologist. Guidance ranges from “avoid it for acidic cooking” to “properly maintained stainless is fine even if scratched” [3][4]. Sensible middle ground: use broken-in pans, limit long acidic simmers, and consider glass or enamelled cast iron for those dishes.
Do I need to worry about a new stainless steel pot?
New pots leach the most because the protective layer hasn’t fully formed. Wash it, use it a few times, and the leaching drops substantially — no need to discard anything [1].
The Bottom Line
Stainless steel is a well-justified kitchen default: durable, coating-free, and stable enough that the nickel and chromium it releases stay below health-concern levels for most people — with the released chromium being the nutritional form, not the toxic one [1]. The honest caveats are small and manageable: new pans and long acidic cooks leach more, quality grades matter, and people with nickel allergy or systemic nickel allergy syndrome have a real reason to be thoughtful and talk to their doctor [3][4]. Buy graded steel, break your pans in, and keep the hours-long tomato sauce for a seasoned pot or a different material. For nearly everyone, stainless is a safe, sensible, buy-it-for-life choice.
Stay curious, stay critical.
Georden
References
- Kamerud KL, Hobbie KA, Anderson KA. “Stainless Steel Leaches Nickel and Chromium into Foods During Cooking.” Journal of Agricultural and Food Chemistry, 2013. Full text (Oregon State University).
- “SAE 316L stainless steel (composition and corrosion resistance).” Wikipedia overview.
- Nickel Institute. “Human Health Fact Sheet 6: Low Nickel Diet for Nickel-Allergic Individuals.”
- “Dietary Nickel as a Cause of Systemic Contact Dermatitis.” Journal of Clinical and Aesthetic Dermatology.
- Health Canada. “The safe use of cookware.”
Georden Jones is the founder of The Peer Review. Read the full story.