Coatings Guide

Coatings Information

What is the best non stick non toxic cookware?

The healthiest non stick cookware is a seasoned cast iron or carbon steel skillet, or a stainless steel pan with some kind of cooking fat in it.

If you are specifically looking for a true non stick coating, enameled cookware would be the next healthiest choice, as it doesn’t have as many mystery ingredients as “ceramic” non-stick coatings do. If it meets Prop 65 requirements, you know it is free of heavy metals that leach into your food, or tested to be minuscule (1/1,000th of the daily limit of exposure.)

Is there a safe non stick fry pan?

Yes, I have them listed here (paywalled).

What is leach testing?

Leach testing is one way to tell how much of a metal actually migrates out of a product into food. It’s a helpful test used in conjunction with XRF testing, to understand whether the lead in a product is bound up in it, and won’t cause harm, or if it’s leaching out into food, and at what level. For leach testing done on cookware, an acid bath method is used. 4% acetic acid solution (essentially, extra strong vinegar) is added to the pot, boiled for 2 hours, then cooled and held at room temperature for 24 hours. After that, samples of the liquid are analyzed for how much lead it contains using Inductively Coupled Plasma Mass Spectrometry (high tech lab equipment). Then, this result is used to back-calculate the equivalent lead content in ppm (or mg/kg) in the pot itself, that is capable of leaching.

Leach tests are designed to greatly overestimate the amount of heavy metals you would possibly be exposed to, to leave lots of room for error and promote less lead exposure. It is very unlikely that you would ever cook food under conditions that are so acidic, or for so long. It gives you essentially a “worst case scenario” result.

Is lead free ceramic glaze actually lead free?

Usually, yes, but since ceramic glaze is made with minerals from the earth, there is still a chance that it has a miniscule amount of lead in it. The FDA regulates this, and explains, “when the pottery is fired at the proper temperature for the proper amount of time, essentially all the lead is bound into the glaze. If any migrates to food, it will be an insignificant amount.” Even though we should all aim for zero lead, it is worth noting that lead is present everywhere — even in vegetables, chocolate, tap water, and bottled water. Often times, lead in present in glazes in amounts even lower than what is found in a vegetable. The best way to know is — not to do XRF testing, which will just show you the presence of lead — but to do leach testing, which will test to make sure any lead is truly bound up in the glaze, and won’t migrate out into food. Read all the details about this in my Lead guide here.

What is enamel vs ceramic glaze vs ceramic non stick?

• Enamel is a mixture of glass and pigments and is fused to metal.

• Ceramic glaze is a mixture of glass and pigments and is fused to ceramic.

• “Ceramic” non-stick is actually a sol-gel, and contains silicon, oxygen, and proprietary (unknown) ingredients. It is a gel sprayed on to many types of cookware surfaces.

What is enameled cookware?

Metal cookware made out of cast iron or aluminum can be coated in enamel, which is essentially a layer of glass and color melted on to the surface. This is different than ceramic non stick coatings! Read more below.

What is enamel made of?

Enamel is a coating made of powdered glass and pigments. The pigments come from naturally occurring metals like cobalt (to make blue), iron (to make green or brown) and neodymium (to make purple.) Lead and cadmium were also used very frequently in the past to make bright colors, though are used less often now. The glass and pigment mixture is heated to a super-high temperature, and melted on to a metal surface that it then fuses with. You’ll see this most commonly on enameled cast iron pots and dutch ovens, and some plates, cups, and bowls.

Is enamel coated cookware non toxic?

It’s not perfect, but it’s relatively low risk, and earns second-healthiest on my rating scale, because we know what iti’s made of — sand and mineral pigments— and it’s easy to test for problems— heavy metal contamination— as opposed to a “ceramic” non stick coating, which is always proprietary and polymer-based.

If comprehensive leach testing is performed, and the enamel doesn’t leach any heavy metals into food, it’s a pretty safe bet. However, only lead and cadmium leach tests are routinely done. Since antimony, arsenic, and cobalt leachate testing usually isn’t done, you don’t know how much, if any, get into your food. It probably isn’t a lot! But, when we don’t know, that uncertainty is where the issue arises and what makes enamel “not perfectly” healthy.

FYI, if you follow anti-lead activist and blogger Tamara Rubin, you know she has found heavy metals including lead, cadmium, antimony, and arsenic in many new (2024 even) enameled cookware and dishware products like dutch ovens, mugs, and plates, using XRF testing. I think it’s important that brands don’t advertise their products as perfectly healthy or heavy metal -free when in fact, there may be trace amounts of these metals detected on their cooking surfaces. However, these metals do not always migrate out of the product into your food — read my information all about this on my Lead page — and so they still can make a relatively safe choice. Bottled water can contain up to 1 ppb (part per billion) of lead, and root vegetables can have up to 20ppb. So, theoretically, using enamel-coated cookware that leaches 1ppb lead during a 24 hour acid bath leach test is even safer than eating some vegetables from a purely lead-focused perspective. Moreover, the amount of metals leached decreases significantly with the more acidic cooking they go through. It is possible (though I obviously can’t guarantee it) that you can do a few rounds of cooking acidic tomato sauces or vinegars for a few hours, dispose of that food, and trust your pot has fewer leachable contaminants in it afterward. Risk is personal — a sliding scale, with lots of grey areas and nuance.

Can arsenic, cobalt, lithium, or antimony leach out of enamel cookware?

Yes, they can. Only lead and cadmium are routinely included in leach testing for cookware and other metals harmful to health like arsenic, cobalt, lithium, and antimony, are not. That’s likely because they are of the highest concern, and more mandatory testing is expensive. A 2011 study argued that it was important to include these in leach testing in Europe, though it hasn’t yet passed through to become law. A more recent paper with suggestions for guidelines was released in 2020 and other efforts are ongoing to include these metals in testing in the future.

Are certain colors of enamel coating safer than others?

No. Even tan or near-white enamel coatings can be made with a mixture of pigments and metals, and there is no consensus amongst the XRF test results I’ve seen across various outlets confirming that one color is consistently better than another in terms of safety. Moreover, brands can change ingredients at any time, so any particular color isn’t necessarily going to have the same make up over time. Even though it has been floated around on the internet that white or tan colors are safer, I would not put a lot of stock in this idea.

Is enamel coated dishware non toxic?

The pigments used to color enameled dishware can contain heavy metals (see question above.) But the risk of migration is typically even lower for dishware than for cookware or bakeware, because acid, heat, and time are what coax metals out into food. If you’re using enameled dishware for mostly cold purposes (like cups for cold water, or bowls and plates for cold/warm food) it is, in my opinion, very low risk, but depending on your health history and risk tolerance, you may choose to avoid it completely.

What is XRF testing?

XRF stands for X-Ray Fluorescence, and it is one way to know what metals are present in a product. XRF testing can be done with a handheld device that looks a little bit like a hot glue gun with a screen on it. You can point it at a product, and the type of x-rays that bounce back will tell you what metals are in it. The screen will display a list of how much of each metal is in it. Handheld machines cost up to $50,000 and you must be trained to use it — because it uses x-ray technology, radiation safety knowledge is needed, and since it is a highly technical instrument, understanding accuracy vs precision, calibration, and how to interpret results is important.

Is XRF testing accurate?

Yes, it can be, as long as the machine is calibrated, and the user is trained.

Is XRF testing or leach testing more accurate?

While they’re both accurate, leach testing is more accurate for “real life” use.

An XRF test may show that the coating in a pot has 100ppm lead in it. A leach test may show that same pot has 20ppm lead in it (read more about ppm, ppb, and limits on lead below). Both methods are useful — in XRF testing, the x-rays bounce off the surface and report back to you that it “sees”100ppm lead. It’s good for knowing about the presence of lead, but not necessarily how it will act in real life. Leach testing on the same pot may tell you that over 24 hours, under acidic conditions, the pot has 20ppm that could potentially leach. This is not the same as what is actually in the leachate solution— you can assume that much less of what the leach test shows would get out under normal cooking conditions. Overall, leach testing gives you a more realistic exposure estimate.

XRF testing and leach testing aren’t perfectly correlated. Sometimes, a high XRF reading will have a very low leachate result, and a lower XRF reading will have a relatively high leachate result. You can see what I mean in the testing done on lead-contaminated aluminum cookware here. This is because it’s not just about the mere presence of lead, it’s also about how it is bound up into the rest of the materials the pot is made of.

What are ceramics made of?

Ceramics are made from clay, which comes from the earth. They are non-metallic. Clay is made up of minerals and metals and naturally-occurring pigments. In your home, tile, plates, glass, and toilets are all made of ceramic. Ceramic is usually, but not always, glazed to make it shiny, colored, or more durable.

What is ceramic glaze made of?

Depending on how glossy and what color it is, the exact mixture will vary, but almost always includes minerals, metals, silica, and pigments. Lead was commonly used in glaze in the past because it makes a really nice, glossy, brightly colored surface. Since the 1970s, lead is used much less often in ceramic glazes, though it is still sometimes detected in modern glazed ceramicware with XRF and leach testing— you can read more about this, as well as how much lead stays in the object vs how much can leach out on my Lead page. This kind of ceramic glaze is what you see on mugs, plates, and handmade pottery.

What is non stick ceramic coating made of?

Silicon and oxygen, which is glass, mixed with other unknown ingredients.

Why do you have “ceramic” in quotation marks?

Because ceramic non stick coating is not actually ceramic (clay), nor is it the glaze used on ceramic bowls, cups, and handmade pottery! It just has the word ceramic in it because it’s applied to cookware like a ceramic glaze is applied to pottery. Confusing! The ingredients are different.

Non stick ceramic coating is a type of sol-gel. Sol-gel was invented around 2008 as a less toxic alternative to PFAS, and contains the silicon, oxygen, and other unknown ingredients that are in a gel-like liquid state. They’re sprayed into cookware and baked on at very high temperatures so that it won’t melt again, as long as you’re cooking at 500F or less. There are a few different brand names of sol-gel, like Thermolon, for example. Different brands have slightly different colors, mixtures, and properties, because they mix different ingredients in with the silicon and oxygen.

Is non stick ceramic coating safe?

The silicon and oxygen part of sol-gel non stick coatings is very safe, as it’s just glass, but it’s the addition of other ingredients that may be less safe. Unfortunately, no non stick pan company discloses their full ingredients. In general, I prefer seeing a full list instead of assurances that it’s safe. A few possibilities include:

• Nano-titanium dioxide: titanium dioxide in its normal, non-nano, form is banned in food products in the EU because it is associated with potential to cause DNA damage when ingested. (It is still used in the US, mostly in processed foods and candies, because it makes the colors look more vibrant.) Nano titanium dioxide is the super-small version of regular titanium dixoide, and is used in non stick ceramic coatings because it adds durability and can act as an antimicrobial. Unfortunately, it is released into the food during cooking, as this study found. Nanoparticles are so small, they cross cell walls, cause oxidative stress, and are generally considered harmful to human health. (This is why you’ll see sunscreens advertise that they use “non-nano zinc”— it’s important!)

• Pigments: you may have noticed that ceramic non stick surfaces come in different colors. These are due to various dyes added to the mixture and it’s very difficult to find information on them, though it seems they may be some combination of naturally-derived flower pigments, synthetic pigments, and metals including cobalt. Some of the pigments may be nano-pigments, which again, are best avoided for human health.

• PFAS: ironically! Most companies use non-stick ceramic coating to replace PTFE/Teflon/PFAS coatings, but not all — some do still use these fluorine-containing compounds for enhanced non-stick properties (like Great Jones, for example.)

Is titanium dioxide safe?

It depends on what form it’s in, and how it’s interacting with you.

• Non-nano titanium dioxide: this is generally safe to touch. If you’re a fan of Yuka, you know they rate it in this form as no risk. Your skin doesn’t absorb it, so it is still commonly used in sunscreens. Ingesting non-nano titanium dioxide has some risks, including the potential to cause DNA damage. It is still used in many candies and other processed foods in the United States, to make them more colorful and appealing to the eye, though it has been banned in food in the EU. It’s also used as part of the coating in many pots and pans to make them a certain color.

• Nano-titanium dioxide: the nano form of anything comes with risks that we are still learning about. Nanoparticles are so small, they can cross cell walls, cause oxidative stress, and are generally considered harmful to human health. For cookware, a nano coating adds durability and can act as an antimicrobial, and is often a part of “ceramic” non stick coatings. Brands generally state that it doesn’t migrate from the coating into your food, but but it is eat least one study has found that isn’t true. It’s possible they’re right, but I worry this is a “regrettable substitution” for PFAS. Until this technology’s impact on human health is better understood, I would exercise caution.

Is HexClad safe?

HexClad is currently a ceramic non stick coating with the brand name of TerraBond. Before, they claimed their coating was PFAS free, but they still used PTFEs, and went through a lawsuit because of that. Though PFAS free ceramic non stick is a relatively OK-ish choice on the scale above, I would have a hard time trusting their current claims.

Which is safer, enamel or “ceramic” non stick?

Enamel is likely safer than ceramic non stick coatings. Enamel is generally made with fewer, known ingredients— glass and pigments— while ceramic non-stick is not actually ceramic, and is made with a proprietary sol-gel mixture of glass and other unknown ingredients. Because PFAS and nanoparticles are sometimes used in ceramic non-stick, this also makes it a less healthy choice than enamel. I have never seen a company that has fully disclosed their ceramic non stick cookware coating ingredients. Theoretically, if one ever did, you could find that it is safer than enamel. Enamel carries some risk due to the heavy metals that are sometimes in the pigment in it, though if you choose a leach tested enamel product, it is very safe.

What are PFAS chemicals?

PFAS stands for perfluoroalkyl and polyfluoroalkyl substances, and is a big umbrella term that covers 3,000 kinds of fluoroplastics. PFAS are all synthetic chemicals that were created by people in the 1940s for waterproofing, oil-resistance, and stain resistance purposes. What all PFAS have in common is fluorine (F) bound to carbon, because these two make a very strong bond together — it is what creates such good resistance to water, oil, and stains. Some of the most popular kinds of PFAS on the market today are PTFE, PFOA, and PFOS. Once PFAS are created, they don’t break down in the environment, which is why they’re often called “forever chemicals.” Unfortunately, they cause many environmental and human health risks.

What is the difference between PFAS vs PTFE vs PFOA vs PFOS?

PFAS is the umbrella term for 3,000 types of fluoroplastics, including PTFE, PFOA, and PFOS.

In non-stick cookings, PTFE is the actual non-stick surface of the pan, and PFOA helps make the PTFE stick to the cookware surface. PFOA and PFOS are two other kinds of PFAS that have been phased out of cookware.

What types of PFAS are used in non stick cookware?

• PFOA, perfluorooctanoic acid. This helped make the PTFE stick to the cookware surface. It was phased out of cookware in 2015 due to health issues.

• HFPO-DA, hexafluoropropylene oxide dimer acid, also called GenX. It’s now considered a “regrettable substitution” for PFOA, as it is just as toxic and also associated with health issues. It is still used commonly even though health issues are arising.

• PFOS, perfluorooctane sulfonic acid. It was phased out of cookware in 2002, though still exists in older pans.

• PTFE, polytetrafluoroethylene, also called by its brand names Teflon, Greblon, Dyneon, QuanTanium, or Granitium. This is still widely used in cookware today because it is relatively stable compared to the other options, however some still can migrate into food and air.

What is GenX non stick?

GenX is a type of PFAS that was created by DuPont to replace PFOA, when PFOA was found to be associated with health issues. Its chemical name is HFPO-DA, or hexafluoropropylene oxide dimer acid. It’s considered a “regrettable substitution” for PFOA, as it is just as toxic and also associated with health issues.

Is PFOA free cookware safe?

No. PFOA is one of the 3,000 types of PFAS. If the pan is advertised as PFOA-free non-stick, it very likely contains one of the other kinds of PFAS. The same goes for PTFE-free. Unless a company states that their pans are totally PFAS free, be wary. PFAS is the umbrella term for all types of fluoroplastics, so truly PFAS-free cookware shouldn’t contain any of them.

Is granitium cookware safe?

No. Granitium is another name for Teflon. It is also PTFE, a type of PFAS that is associated with many health risks. It may be blended with ceramic particles or other metals and advertised as PFOA-free, but it still contains PFAS.

Do PFAS migrate from cookware into your food?

Yes. Cooking on high heat releases PFAS into food and the air, and cooking utensils can scratch the coating, releasing them directly into your food as well. PTFE is the main type of PFAS on the surface of pots and pans, and even though it is more stable than other types of PFAS, and research is still developing, it does appear to leach into food just like any other coating does, too.

Is nanobond cookware safe? Is nano coated cookware safe?

No. Nanoparticles are so small, they can cross cell walls, cause oxidative stress, and are generally considered harmful to human health. When they’re specifically made for drug delivery that may be OK, but outside of very intentional use like this, nanomaterials are so small that they can cause problems in the human body. They are much more reactive than their normal sized counterparts, and often in ways we don’t fully understand yet, as the technology is still relatively new. So, while regular titanium would be a perfectly safe metal surface to cook on, nano-titanium is not necessarily safe. It adds durability and can act as an antimicrobial, but it is released into the food during cooking, as this study found. Until this technology’s impact on human health is better understood, I would exercise caution.