Learn ➜ Material Health Guides ➜ Coatings Guide
Coatings Guide
Your Evidence-Based Safety Guide to Ceramic Glaze, Enamel, Non-Stick Cookware, Stain-Resistant Rug Finishes, Antimicrobial and Anti-Fingerprint Coatings, and More
Updated December 2025
Meg is the founder and owner of Interior Medicine. She provides evidence-based guidance on creating healthier homes through transparent material analysis and peer-reviewed research to help you make informed decisions about household products.
Coating Rating Scale
This scale is a summary of all the information below. Scales keep me consistent and unbiased as I rate and rank products for their potential impact on your health in the Interior Medicine Shop. Your situation and risk tolerance may differ—these are guides, not absolute rules.
Keep reading for the full breakdown on why enamel is safer than ceramic non-stick, what makes PFAS coatings risky, and how to make smart decisions about coated surfaces in your home.
Kitchenware Coatings
Non-Stick Cookware Coatings Comparison
What is enamel vs ceramic glaze vs ceramic non stick vs regular 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.
Traditional non-stick coatings are made with PFAS, a large class of chemicals that includes thousands of types, including Teflon (PTFE), PFOA, GenX, Granitium, and many others.
What is the best non-stick non-toxic cookware?
Cookware with enamel or true ceramic glaze that meets Prop 65 requirements for lead and cadmium is the healthiest choice of non-stick cookware. It is healthier than “ceramic” non-stick, which is made of an unknown list of ingredients. Read more below to understand more about why, or see the Non-Toxic Cookware I recommend.
Is there a safe non stick fry pan?
Yes! See the safer non-stick pots and pans, bakeware, dutch ovens and slow cookers that are made with truly non-toxic materials and have good ingredient transparency (all are part of the Look Inside section of the website.)
Enamel Coatings: Glass Fused to Metal
What is enamel coating made of?
Enamel is powdered glass mixed with mineral pigments, heated to extreme temperatures, and fused onto metal surfaces like cast iron or steel. The pigments come from naturally occurring minerals and metals: cobalt (blue), iron (green/brown), neodymium (purple).
Lead and cadmium were used frequently in the past for bright colors, but are still used occasionally today. You'll see enamel most commonly on dutch ovens, roasting pans, and some dishware.
Is enamel cookware safe?
It's not perfect, but it’s relatively low risk because we know exactly what it's made of—sand and mineral or metallic pigments—and it's straightforward to test for problems (heavy metal contamination). This is unlike "ceramic" non-stick coatings, which are always proprietary (secret).
If comprehensive leach testing confirms the enamel doesn't leach heavy metals into food, it's a safe choice. However, only lead and cadmium leach tests are routinely performed. Antimony, arsenic, and cobalt leachate testing usually isn't done, so you don't know how much, if any, migrates into your food. It's probably minimal, but that uncertainty is what keeps enamel from being "perfectly" healthy.
The reality of heavy metals in enamel:
Anti-lead bloggers have found lead, cadmium, antimony, and arsenic in many new (even 2024) enameled products using XRF testing. I agree with these bloggers that brands shouldn't advertise products as perfectly healthy or heavy metal-free when trace amounts may be detectable. However, where I don’t always agree is that they are a total danger to you. Detection doesn't equal migration—these metals don't always leach from the product into your food. It can be an uncomfortable concept to grapple with— hearing over and over again from experts that there is no safe level of lead, but also hearing, from those same experts, that some lead is OK. It’s true, all lead is bad for us. However, because lead is inextricably bound up in other, healthy things, we accept certain levels of it as an unfortunate but inescapable trade-off. Read my full address of this in the Lead Paradox section of my Metal Guide — the same concept applies to Cadmium.
The amount of metals leached decreases significantly with repeated acidic cooking. You could potentially do several rounds of cooking acidic tomato sauces or vinegars for a few hours, dispose of that food, and reduce leachable contaminants. Risk is personal—a sliding scale with grey areas and nuance.
Can arsenic, cobalt, lithium, or antimony leach from enamel cookware?
Yes, they can.
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.
That said, the presence of heavy metals in enamel doesn’t mean they can escape from it into your food. Detection doesn't equal migration. It can be an uncomfortable concept to grapple with— hearing over and over again from experts that there is no safe level of these heavy metals, but also seeing them being legally used in home products. Read my full address of this in the Lead Paradox section of my Metal Guide — the same concept applies to all heavy metals.
Are certain enamel colors safer than others?
No, unfortunately even these light colors have show positive results on blogger XRF tests. While XRF testing only detects the presence of these, and not how much they’d leach out (requiring a leach test), I think it’s important to know that light colors can still contain heavy metals. Moreover, brands can change suppliers or ingredients anytime, so color composition isn't guaranteed over time. While the internet claims white or tan colors are safer, I wouldn't rely on this.
Is enamel dishware safe?
Dishware coated in enamel is generally safer than cookware or bakeware that is!
Even if the pigments contain heavy metals (see above), migration risk is typically lower for dishware than cookware because acid, heat, and time are what coax metals out. For cold uses (cups for water, bowls and plates for cold/warm food), it's very low risk. The risk would be higher for drinking acidic, hot coffee and tea.
Depending on your health history and risk tolerance, you may choose to avoid it completely.
What about cadmium in enamel?
Cadmium is naturally present in soil, clay, and earth pigments, making it common in enamel glazes. Le Creuset lists cadmium pigment on many products. While they disclose it (Prop 65 requirement) and it's typically on the exterior not touching food, people understandably find this concerning. Choose enamel cookware with third-party leach testing confirming it meets Prop 65 requirements for both lead and cadmium. If you’re feeling shocked that Cadmium is still allowed in enamel and foodware, I hear you— read my address of it on the my Metal Guide in the Cadmium section.
Ceramic Glaze Safety
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 Metal Guide in the Lead Leaching section. This kind of ceramic glaze is what you see on mugs, plates, and handmade pottery.
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.”
We should aim for zero lead, but lead exists everywhere—in vegetables, chocolate, tap water, and soil. Lead in glazes often represents an even lower exposure than what you’d get from vegetables, but some people understandably want to avoid even this. The best way to know what you’d be exposed to isn't XRF testing (which only shows presence) but leach testing, which confirms lead is bound in the glaze and how much, if any, will migrate into food. Read all the details about this in the Lead Testing section of my Metal Guide.
"Ceramic" Non-Stick: Not Actually Ceramic
What is ceramic non-stick coating made of?
Silicon and oxygen (glass) mixed with unknown proprietary ingredients.
Why the quotation marks around "ceramic"?
Because ceramic non-stick coating isn't actual ceramic (clay), nor is it the glaze on ceramic bowls and pottery. It just has "ceramic" in the name because it's applied to cookware like ceramic glaze is applied to pottery. Confusing, but the ingredients are completely different.
Ceramic non-stick is a sol-gel — invented around 2008 as a less toxic PFAS alternative. It contains silicon, oxygen, and other unknown ingredients in a gel-like liquid state. The gel is sprayed into cookware and baked at very high temperatures so it won't melt as long as you cook below 500°F. Different brand names (like Thermolon) have slightly different colors, mixtures, and properties because they add different proprietary ingredients to the silicon and oxygen base.
Is ceramic non-stick coating safe?
The silicon and oxygen component is very safe—it's just glass. But the additional ingredients may be less safe. Unfortunately, no non-stick pan company discloses full ingredients, not even “non-toxic non-stick” brands. I prefer seeing complete ingredient lists instead of assurances of safety, so I can make the call on whether or not it’s safe enough for me. Here are a few potential additional ingredients mixed in with the sol-gel:
Problematic ingredients in ceramic non-stick coatings:
Nano-titanium dioxide: Regular (non-nano) titanium dioxide is banned in EU food products because it potentially causes DNA damage when ingested. It's still used in US processed foods and candies for vibrant colors. Nano titanium dioxide—the super-small version—is used in ceramic non-stick for durability and antimicrobial properties. It's 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 sunscreens advertise "non-nano zinc"—it matters.)
Pigments: Ceramic non-stick surfaces come in various colors from added dyes. It’s very difficult to find information on these dyes, but they appear to be combinations of naturally-derived flower pigments, synthetic pigments, and metals including cobalt. Some may be nano-pigments, best avoided for human health.
PFAS: ironically, some companies use non-stick ceramic coating to replace PTFE/Teflon/PFAS coatings, but not all. Some do still use these PFAS for enhanced non-stick properties (like Great Jones, for example.)
Is titanium dioxide safe in cookware coatings?
It depends on the form and how it interacts with you.
Non-nano titanium dioxide: Generally safe to touch. Skin doesn't absorb it, so it's still common in sunscreens. Yuka rates it in this form as no risk. Ingesting non-nano titanium dioxide has 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: Nano versions of elements act completely differently than normal-sized counterparts. Nanoparticles cross cell walls, cause oxidative stress, and are generally considered harmful to human health. For cookware, 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 at 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.
Enamel vs ceramic non-stick: which is safer?
Enamel is likely safer. Enamel has fewer, known ingredients (glass and pigments) while ceramic non-stick is proprietary sol-gel with glass plus unknown ingredients. Because PFAS and nanoparticles are sometimes used in ceramic non-stick, it's a less healthy choice than enamel. I've never seen a company fully disclose ceramic non-stick ingredients. Theoretically, if one did, you might find it safer than enamel. Enamel carries some risk from heavy metals in pigments, though leach-tested enamel products are very safe.
PFAS Non-Stick: The "Forever Chemicals"
What are PFAS chemicals?
PFAS (perfluoroalkyl and polyfluoroalkyl substances) is a big umbrella term covering 3,000 kinds of fluoroplastics. PFAS are synthetic chemicals created in the 1940s for waterproofing, oil-resistance, and stain resistance. What all PFAS share: fluorine (F) bound to carbon. These two create a very strong bond—what makes them so resistant to water, oil, and stains.
Popular PFAS types: PTFE, PFOA, and PFOS. Once created, PFAS don't break down in the environment—why they're called "forever chemicals." They cause many environmental and human health risks.
PFAS vs PTFE vs PFOA vs PFOS: what's the difference?
PFAS is the umbrella term for 3,000 fluoroplastic types, including PTFE, PFOA, and PFOS.
In non-stick cookware, PTFE is the actual non-stick surface, and PFOA helped make PTFE stick to the cookware surface. PFOA and PFOS are two PFAS types 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 still associated with health issues. It is still used commonly despite emerging health concerns.
PFOS (perfluorooctane sulfonic acid): IPhased 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.
Is PFOA free cookware safe?
No. PFOA is one of 3,000 PFAS types. If a pan is advertised as PFOA-free non-stick, it very likely contains another PFAS type. Same goes for PTFE-free. Unless a company states pans are totally PFAS-free, be wary. PFAS is the umbrella term for all fluoroplastics, so truly PFAS-free cookware shouldn't contain any.
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 HexClad safe?
HexClad currently uses ceramic non-stick coating with brand name TerraBond. Previously, they claimed their coating was PFAS free, but they still used PTFEs, leading to a lawsuit. Though PFAS-free ceramic non-stick is a relatively acceptable on my scale, I'd have difficulty trusting their current claims.
Is Granitium cookware safe?
No. Granitium is another name for Teflon—also PTFE, a PFAS type associated with many health risks. It may be blended with ceramic particles or metals and advertised as PFOA-free, but 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.
What are anti-fingerprint coatings made of?
Anti-fingerprint coatings (also called oleophobic coatings) are typically made from fluoropolymers—yes, the same family as PFAS. These create an ultra-thin layer that repels skin oils and water, preventing visible fingerprints and smudges. You'll find them on stainless steel appliances, bathroom mirrors, and glass surfaces.
Are anti-fingerprint coatings on appliances toxic?
Once applied and cured, they're relatively stable and don't significantly off-gas. The fluoropolymer layer is extremely thin (nanometers thick) and bonded to the surface. Since they’re bonded to the metal appliance surface, they likely do not fall off as readily as they do from textiles.
However, when these surfaces are scratched with normal wear and tear, cleaned with abrasive materials, or exposed to heat, small amounts of fluorinated compounds can be released. Also, the fact that PFAS are still being created and sold means toxic industry waste and harmful exposures for the workers.
Should I avoid anti-fingerprint stainless steel appliances?
Yes, if possible, though I recognize it’s harder and harder to avoid now when buying new appliances. If choosing between identical appliances, I'd choose standard stainless steel without coating. If you already have anti-fingerprint appliances, use them normally but avoid abrasive cleaners that damage the coating and increase PFAS release. Wash your hands regularly, dust weekly, and clean your indoor air by ventilating or using an air purifier that captures PFAS. Standard stainless steel is easier to keep truly clean anyway—you can use any cleaner without worrying about damaging a coating.
What are self-cleaning glass coatings made of?
Self-cleaning coatings use one of two technologies:
Hydrophobic coatings: Made with PFAS or silicone-based compounds that repel water, causing it to bead up and roll off, taking dirt with it.
Photocatalytic coatings: Made with nano-titanium dioxide that uses UV light to break down organic dirt and create a super-hydrophilic (water-loving) surface. Water sheets off instead of beading, carrying dirt away. Read more about nanotitanium coatings by jumping down below.
Are self-cleaning shower door coatings safe?
It depends on the type.
Hydrophobic coatings using fluoropolymers are essentially PFAS treatments. Studies show that homes with products with water-repellent coatings contributed to elevated PFAS levels in household dust, suggesting ongoing low-level release.
Silicone-based hydrophobic coatings are likely safest of the three options, though long-term data is limited. In general, silicone coatings are relatively inert once cured and don't release concerning levels of volatile compounds.
(Photocatalytic coatings containing nano-titanium dioxide raise the same concerns as other nanoparticle applications. Research from 2021 examining photocatalytic coatings found that while they're effective at breaking down organic matter, they also release titanium dioxide nanoparticles, especially when surfaces are cleaned or scrubbed. Read more about nanotitanium coatings by jumping down below.)
Do self-cleaning coatings actually work?
Somewhat, but they're not magic. They reduce soap scum and water spot accumulation but don't eliminate the need for cleaning. Consumer testing finds that self-cleaning glass does require cleaning less frequently than uncoated glass, but still needs regular maintenance. The coatings degrade over time with use and cleaning, losing effectiveness within 1-3 years. If the coating is made of PFAS, degrading over time = PFAS release into your home environment.
Regular cleaning of standard glass is healthier and more effective long-term than relying on potentially problematic coatings.
Nanoparticles
Are nano-coated pans safe? Is nanobond cookware safe?
No. Nanobond cookware is made with nano-size titanium dioxide.
While titanium is safe, the nanoparticle version of it and other substances 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.
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.
Undamaged coatings don't release nanoparticles until exposed to temperatures above 500°C—much higher than normal cooking. However, scratches or surface damage (which occurs with normal use) leads to significant nanoparticle release at typical cooking temperatures
What are antimicrobial coatings and where are they used?
Antimicrobial coatings contain substances that are theoretically designed to kill bacteria, viruses, and fungi on contact. They’re becoming more and more popular, and are showing up on refrigerator handles, dishwasher interiors, washing machine drums, countertop surfaces, and other high-touch areas. The most common antimicrobial agents are silver nanoparticles, copper compounds, and zinc compounds.
Are silver nanoparticle antimicrobial coatings safe?
It’s unclear, but the research is concerning. Silver nanoparticles are extremely effective at killing microorganisms, which is why they're popular in consumer products. However, silver nanoparticles can become airborne during cleaning or surface wear, leading to inhalation exposure and are detectable in house dust from homes with treated appliances, suggesting chronic low-level exposure through normal use. Studies on silver nanoparticle toxicity show they can accumulate in organs, cross the blood-brain barrier, and cause oxidative stress and inflammation.
So while silver nanoparticles aren't in direct food contact like cookware nanoparticles, you're touching these surfaces daily and potentially inhaling particles released during cleaning.
Do antimicrobial coatings actually prevent illness?
Not meaningfully. I think they are more designed to play into humans fears about microbes— a reminder that the vast majority of them are probiotic and good for us! Antimicrobial-treated surfaces in homes don't reduce illness rates compared to regular surfaces with normal cleaning. The coatings kill some bacteria on contact, but they don't replace proper cleaning, and bacteria recolonize surfaces quickly anyway. Regular cleaning with soap and water is more effective than antimicrobial coatings and doesn't involve nanoparticle exposure.
Should I avoid appliances with antimicrobial coatings?
Yes, if you can. If you have a choice between identical appliances with and without antimicrobial treatment, choose without. The coating provides minimal benefit while introducing uncertain health risks. If your current appliances have antimicrobial coatings, don't stress—just clean them regularly with normal cleaning products, wash your hands regularly, and ventilate or use an air purifier every day!
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