Quick take
- A 2013 laboratory study found that nickel and chromium can move from stainless steel into acidic food during long simulated cooking, with the most coming from new steel.1
- Another study of 19 stainless utensils found that, apart from new pans on their first use, the nickel they added to everyday portions was small.3
- People with a diagnosed nickel allergy may want to talk with a clinician about cookware.45
- Stainless steel is not a PFAS question by default, but a “stainless” pan can still carry a nonstick coating. In one published test, one did.7
First, what “stainless” means
Stainless steel is an iron-and-chromium alloy. The EDQM technical guide says it always contains at least 10.5% chromium, which forms a very thin protective surface layer that helps it resist corrosion, and that many food-contact grades also include nickel.2 Clemson’s food-safety factsheet describes it as durable, hard and non-porous.6
The grade numbers you see on pots (18/10, 304, 316) describe how much chromium and nickel the steel contains. The 2013 study notes that grades 304 and 316 are the most commonly used in food and beverage settings.1
What the research found
Nickel and chromium are in many foods already. The question researchers ask is how much extra a pan adds.
A lab simulation. Researchers at Oregon State University ran simulated cooking of commercial tomato sauce, which is acidic, with stainless steel samples and also in a grade 316 saucepan. They reported that nickel and chromium in the sauce rose, that new steel leached the most, and that leaching dropped with repeated cooking cycles before levelling off.1 The authors write that stainless cookware “can be an overlooked source of nickel and chromium.”1
A household-style test. A 1995 study ran an extensive series of cooking operations in 19 stainless steel utensils. It reported that, apart from new pans on first use, the nickel they contributed was small, in the range of 0 to 8 micrograms per standard portion. It found that new pans first used with acidic fruit could pick up more, and that this did not recur on later use.3
Stainless steel cookware can be an overlooked source of nickel and chromium.
These two results can both be true: the studies used different foods, times and set-ups, and the 2013 authors themselves note that earlier studies reached inconsistent conclusions.1
See the evidence: studies and limits side by side
| Source | What it did | What it reported |
|---|---|---|
| Kamerud et al., 2013 | Simulated cooking of four commercial tomato sauces with stainless steel samples equivalent to grades 304 and 316, plus a 2-quart grade 316 saucepan, over several cooking times and ten repeated cycles.1 | Leaching was highest in the first cooking cycle and fell, then levelled after about six cycles. In the saucepan test, nickel in the sauce reached 3.84 mg/kg after a 20-hour cook, against 0.130 mg/kg in sauce cooked without stainless steel.1 |
| Flint and Packirisamy, 1995 | Household-style cooking in 19 Cr/9 Ni utensils.3 | Negligible nickel contribution apart from new pans on first use; worst observed new-pan case was about one fifth of an average daily intake.3 |
| EDQM technical guide, 2024 | Reviews published release studies and lists specific release limits (SRLs) for metals in food-contact articles.2 | Listed limits of 0.14 mg/kg of food for nickel and 1 mg/kg for chromium.2 It also describes studies where release into acidic simulants stayed below those limits.2 |
How to read this: the 2013 saucepan figure came from a 20-hour simulation, far longer than a normal dinner, and in the steel-sample tests the sauce touched roughly ten times more steel surface per amount of sauce than it did in the saucepan, by the authors’ own comparison.1 The European limits are guidance for manufacturers and regulators in Europe; we did not find an equivalent U.S. limit for stainless cookware, and that is a gap in our research, not a statement about the law.2
Who may want to pay closer attention
The American Academy of Dermatology calls nickel one of the most common causes of allergic contact dermatitis and recommends avoiding nickel-containing objects if you have a nickel allergy. For people who are extremely sensitive, it also lists foods that are high in nickel.4 Harvard’s Nutrition Source says that cooking acidic foods like tomatoes, vinegar and citrus in stainless steel can raise their nickel content, that a nickel-free diet is impossible, and that using a low-nickel diet for suspected systemic reactions remains controversial.5
Not medical advice
This page is general information about cookware materials. If you have a nickel allergy, a rash you can’t explain, or any health concern about metals in food, talk to a clinician or a dermatologist before changing how you cook.
Everyday habits that follow from the research
The first two rows are our reading of the studies, not medical advice. The rest follow published care guidance.
| Situation | Why it comes up | Do | Don’t |
|---|---|---|---|
| A brand-new pan | New steel released the most in both studies.13 | Wash it well, and for its first few uses lean on foods that aren’t long-simmered and acidic. | Make a long tomato-sauce simmer your first recipe. |
| Long, acidic simmers | Time and acidity were what raised release in the 2013 study.1 | Keep simmers to what the recipe needs. | Leave acidic leftovers sitting in the pan. |
| Sticking | The Ecology Center says the cook can avoid sticking by using oil or butter and heating the pan sufficiently before adding food.7 | Heat the pan, then add the fat, then the food. | Add food to a cold, dry pan. |
| Salt | Clemson notes that undissolved salt can pit steel surfaces.6 Caraway’s own care guide for its stainless line says to salt once food is hot.9 | Dissolve salt in hot food. | Pour salt onto a cold pan. |
| Quick cleanup | Clemson reports that manufacturers caution against letting acidic or salty foods stay in stainless steel for long periods.6 | Wash soon after cooking. | Soak overnight with leftovers. |
Stainless steel and PFAS
PFAS questions mostly arise with coatings. The Ecology Center lists stainless steel among durable, uncoated alternatives to PTFE-coated pans, and Consumer Reports says many uncoated pans are unlikely to contain PFAS. Neither tested uncoated stainless pans; their test sets were nonstick pans.78 So our confidence here is a material-based expectation, not a lab result. It also depends on the pan really being uncoated.
That last point matters. In the Ecology Center’s coating analysis, a pan listed as the Cuisinart Classic Stainless Steel 8 in Non-stick Skillet was found to carry a PTFE coating, and the company’s claim on it read “QuanTanium non-stick interior.”7 In that case the word “stainless” in the product name did not tell you whether the cooking surface was coated. Check whether the surface is described as uncoated, and read our label decoder and the PFAS-free cookware explainer.
Questions worth asking before you buy
- Is the cooking surface plain, uncoated stainless steel, and does the brand say so in words?
- Does the brand tell you the grade or the construction (single metal, or layers around a core)?
- Does the handle or lid use any coating or other material you would want to know about?
- Do you cook a lot of long, acidic simmers? Our enameled cast iron guide looks at one alternative.
- Does the brand’s care page match how you cook (hand wash, heat range, salt)?
What we don’t know
- Whether the lab-simulation numbers translate to what a typical home cook adds to a typical meal. The two studies we cite disagree in emphasis.13
- PFAS test results for specific uncoated stainless pans. We did not find any.
- How different stainless grades compare in everyday use beyond the grades in the 2013 study.
- A U.S. regulatory limit for nickel or chromium release from stainless cookware. We did not find one.
- We read the 1995 study as an abstract only.3
Related: cookware materials compared, how to care for your cookware and the kitchen registry guide.