Caraway Cookware and Heavy Metals: Which Tests Should We Believe?

Written by Leigh Matthews, BA Hons, H.Dip. NT

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Leigh Matthews, BA Hons, H.Dip. NT

Sustainability Expert

Leigh Matthews is a sustainability expert and long time vegan. Her work on solar policy has been published in Canada's National Observer.

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Several readers have contacted us with concerns over potential greenwashing by Caraway Home. As one of our top recommended brands for non-stick bakeware and cookware, we take these concerns seriously. After digging into the science of XRF spectrometry, the sol-gel process, and the marketing claims made by Caraway, we stand by our recommendation that this company offers some of the best ceramic non-stick cookware currently available. That said, there are totally non-toxic, more eco-friendly types of cookware we recommend more.

Caraway Home markets its pots, pans, and bakeware as “Quality cookware, without chemicals.” Is Caraway Home guilty of greenwashing, though? Some of our readers think so, which prompted us to dig a little deeper and give the company a good (Teflon-free) grilling.

TLDR

What follows is a long article, however, for those concerned about home testing of Caraway Cookware by blogger Lead Safe Mama, here is our bottom line. As things stand, there’s no evidence that Caraway cookware will leach toxic heavy metals into food. In fact, there’s robust evidence that the ceramic coating doesn’t leach heavy metals and doesn’t contain lead or cadmium. For us, certified laboratory testing carries greater weight than handheld XRF testing of used cookware by one (albeit well-intentioned and well-regarded!) researcher.

Caraway Home’s marketing claims

Caraway Home uses some fairly common marketing tactics to promote its cookware and bakeware as being healthier for people and planet. These claims include:

  • “Quality cookware, without chemicals”
  • “Made with naturally smooth ceramic, not synthetics like polytetrafluoroethylene (such as Teflon®)”
  • “Non-toxic – A mineral-based coating that won’t leach toxic materials into your clean & healthy ingredients”
  • “High quality ceramic-coated aluminum cookware free of PTFE (such as Teflon®), lead, cadmium, and other toxic materials that can make their way into your food.”
  • “Our cookware set’s coating does not include potentially toxic materials like PFOA, PTFE, other PFAs, lead, cadmium, or toxic metals.”

Outside of the cookware and bakeware itself, Caraway also makes claims about its manufacturing and packaging:

  1. “Releases up to 60% less CO2 when produced compared to traditional non-stick coatings”
  2. “Ethical Manufacturing – We support BSCI and SMETA manufacturing partners where employees are safe, paid fairly, given benefits, and work regulated hours.”
  3. “Thoughtful Packaging – Shipped in recycled cardboard with zero plastic bags, low impact print dyes, and 100% biodegradable cork trivets.”

Let’s take each of these claims in turn.

Caraway ships its products in eco-friendly packaging.

“Releases up to 60% less CO2 when produced compared to traditional non-stick coatings”

This claim sounds good but gets Caraway Home off to a bad start in terms of greenwashing. The company provides no substantive evidence to back up this claim, relying instead on the idea that the sol-gel process it uses is generally less energy intensive than the creation of PTFE non-stick pans.

It also gets a thumbs-down from us because the claim only matters if you assume the cookware will last for a long time. In fact, almost all ceramic-coated cookware will need replacing in just two or three years (even if you look after it well). This means the carbon footprint of a ceramic pan is much higher than that of cast iron or carbon steel, or stainless steel. Even a PTFE pan will last a bit longer than ceramic-coated if treated well (though it’s still worse for the environment overall).

In short, Caraway Home is definitely leaning into greenwashing territory for this claim.

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“Ethical Manufacturing”

Caraway Home claims to produce its wares using ethical manufacturing. To this end, the company says it ‘supports’ BSCI and SMETA manufacturing partners. These initialisms stand for:

Business Social Compliance Initiative (BSCI) – a supply chain management system with a Code of Conduct encompassing social compliance and improvements within farms and factories in a company’s supply chain

Sedex Member Ethical Trade Audit (SMETA) – The Supplier Ethical Data Exchange (Sedex) is a non-profit organization that helps companies improve and maintain responsible and ethical business practices in global supply chains.

In short, Caraway Home focuses on working with factories and suppliers that pay a fair wage, provide employee benefits, prohibit child and forced labor, regulate work hours, and ensure safe working conditions. Note, though, that Caraway Home doesn’t exclusively use Fair Trade factory partners or even BSCI and SMETA manufacturing partners. It just ‘supports’ the use of them.

While better than nothing, we’d definitely like to see a more fulsome commitment to ethical manufacturing to be convinced this marketing phrase means something at Caraway Home. So, greenwashing? Possibly.

“Thoughtful Packaging”

Caraway Home does get top marks for its shipping materials and practices. It ships everything in recycled cardboard with no plastic bags. The cardboard can be recycled and is printed using low impact ink.

Caraway Home also uses fully biodegradable cork trivets to protect the cookware and bakeware in transit. Consumers can reuse these at home as regular trivets to protect surfaces. You can also repurpose them for art projects or to elevate planters on a deck, or crumble them into your home compost or pop them in municipal compost.

Greenwashing? Nope.

“Quality cookware, without chemicals”

Given that water, and the carbon and iron that makes up stainless steel, are chemicals, this statement lacks nuance and immediately undermines confidence in the company.

What Caraway Home probably should say is that the cookware is made without the intentional use of synthetic chemicals most consumers now worry about, i.e., Teflon. Not quite as pithy, but more accurate, I’d wager. The company could also have gone with ‘Quality cookware, without Teflon.’

While the claim of being made ‘without chemicals’ is clearly silly, its intention isn’t necessarily greenwashing. To be guilty of greenwashing, Caraway Home would have to either intentionally use chemicals (by which the company appears to mean ‘synthetic chemicals’) or fail to disclose the presence of harmful chemical contaminants it didn’t intentionally use during manufacturing.

Given that Caraway Home doesn’t disclose its proprietary ceramic coating, it is easy to accuse the company of greenwashing. However, the company does disclose third-party testing showing no detectable levels of the toxic chemicals most consumers worry about in cookware and bakeware (i.e., lead, cadmium, and PTFE).

Looked at another way, Caraway Home may intend this claim to mean the cookware is made entirely without chemicals toxic to human health. This is a bit more problematic, given that it’s possible the cookware contains some chemical elements, like titanium dioxide, that can be harmful to human health if they leach and are absorbed through food.

Caraway Home does have evidence of third-party tests showing no detectable leaching of titanium and other metals, though.

Our verdict, then, is that, while unfortunate in its lack of nuance, this statement doesn’t amount to full-on greenwashing as such. It’s got the potential to be deceptive, though, especially if Caraway Home does use titanium dioxide in its surface coating.

Cooking dinner with Caraway non-toxic cookware

“Made with naturally smooth ceramic, not synthetics like polytetrafluoroethylene (such as Teflon®)”

Like the ‘without chemicals’ statement, the idea that a sol-gel ceramic coating is not synthetic is largely about interpretation. Similarly, the idea of something being ‘naturally smooth’ is a bit tricksy and rather subjective.

Ceramic-coated cookware is also not technically ceramic, given that pure ceramic is made with clay, minerals, and sand (silica). The ceramic coating used to make cookware typically comprises silica and some minerals, but it isn’t clay fired in a hot oven and glazed to create waterproof ceramic bakeware or cookware.

The (subjectively smooth, per our experience) ‘ceramic’ coating on Caraway pans is proprietary, meaning we don’t know exactly what is in there. I’ve asked Caraway Home to provide a list of the ceramic precursors, solvents (which could just be water or alcohol), and activators. In lieu of such information, what we have instead are third-party tests that confirm no detectable levels of PTFE (or PFAS), lead, cadmium, or mercury.

Our verdict: While the statement is a bit wishy-washy, it doesn’t really amount to greenwashing. There are no synthetic chemicals like PTFE in Caraway cookware and the product is made with what most consumers would reasonably recognize as a smooth ceramic coating.

“Non-toxic – A mineral-based coating that won’t leach toxic materials into your clean & healthy ingredients”

In the absence of the company’s proprietary formula, we have no idea what’s actually in this ‘mineral-based coating.’ However, it’s extremely likely, given information in the company’s patent, that the coating largely comprises silicon dioxide or zirconium oxide.

There is a chance that Caraway Home uses titanium dioxide nanoparticles to make the sol-gel. However, third-party tests show no detectable titanium leaching from the surface coating when exposed to an acidic solution at 100 degrees Celsius for two hours (twice). Similarly, the tests show no detectable level of mercury, cadmium, cobalt, lead, or other toxic or potentially toxic metals in two or three rounds of tests (lead and cadmium testing).

As we’ve already seen, the pans are made without PTFE and other forever chemicals. This means you won’t risk these leaching into your food when using the cookware or bakeware.

Where it gets tricky is in Caraway Home’s exact wording. The claim is that the cookware doesn’t contain chemicals or materials that will leach into food. This could imply that the product itself isn’t free of those materials, just that they won’t leach into food. Elsewhere, though, Caraway Home does claim its coating is free of toxic heavy metals.

Per third-party tests, the ceramic surface doesn’t leach detectable levels of heavy metals. Analysis of the coating itself (for Prop 65) also shows no detectable lead or cadmium. This is per the standard test used to detect lead in paint by the Consumer Product Safety Commission (CPSC).

Interestingly, at least one independent researcher has reported that Caraway Home cookware’s ceramic tested positive for lead, cadmium, and titanium, among other metals. We discuss the relevance of these results below.

Our verdict is that this statement and the one below are close to greenwashing. At minimum, they are sneaky copywriting. Is this reason enough to avoid Caraway Home, though? Not necessarily. After all, Caraway Home also explicitly claims its cookware coating is free of toxic heavy metals.

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“High quality ceramic-coated aluminum cookware free of PTFE (such as Teflon®), lead, cadmium, and other toxic materials that can make their way into your food.”

The claim to be high quality is obviously subjective but seems to bear up given most customer experiences. Bear in mind, though, that any ceramic-coated cookware is going to need babying to keep it in good condition. Even then, it will never be as durable as cast iron, stainless steel, or carbon steel. Eventually, the surface coating of any bonded metal-ceramic cookware will get scratched, crack, or otherwise degrade. It loses its non-stick properties and will need replacing.

Regarding the second part of this statement, third-party testing suggests the cookware is free of PTFE, lead, cadmium, and several other toxic heavy metals. Again, though, the wording is tricky. On its own, the phrasing offers an out for Caraway Home if the pans themselves did contain these chemicals, as long as they don’t leach into food under normal use conditions.

As we’ve seen, though, Caraway Home also states that the coating contains no toxic heavy metals. What’s more, the products pass third-party tests showing no lead or cadmium in the actual coating material. This offers some assurance that the claims aren’t greenwashing and are credible.

“Our cookware set’s coating does not include potentially toxic materials like PFOA, PTFE, other PFAs, lead, cadmium, or toxic metals.”

Finally, Caraway Home’s big claim: the cookware coating does not include PFOA, PTFE, other PFAS, lead, cadmium, or toxic metals. This is a far clearer and stronger statement than that it won’t leach these chemicals into your food.

Again, without knowing exactly what’s in the company’s proprietary ceramic coating, we can’t confirm the truth of this statement. What we can see, however, is that reliable third-party tests show no trace of lead or cadmium in the cookware. Ideally, the company would use the same tests to show no titanium, mercury, antimony, or other heavy metals of concern.

Unfortunately, all we have is one independent researcher’s at-home tests suggesting the cookware contains titanium and other troublesome metals. Whether these tests are reliable is hard to say (see below).

What we’re left with, then, is an option to give Caraway Home the benefit of the doubt based on its tests for lead and cadmium. We can also, as consumers and consumer advocates, contact Caraway to ask for more comprehensive information and testing.

Before our final verdict on Caraway Home, let’s discuss the safety of sol-gel ceramic cookware and XRF testing reliability.

What is sol-gel ceramic cookware?

The sol-gel method is a common chemical process where a ‘ceramic’ coating is applied as a liquid to a substrate. In the case of ceramic-coated cookware, the sol-gel is applied to a metal surface before it hardens. This creates a smooth, nonporous surface that is non-stick without the need for PTFE or other forever chemicals.

The sol-gel process involves dissolving the ceramic precursor(s) in a liquid, usually water or alcohol. The ceramic precursors are silica (i.e., sand), just as with conventional ceramic, and elements such as zirconium, iron, and titanium. These can increase the hardness of the coating or confer other properties.

Next, the sol-gel is activated by adding an acid or base, such as hydrochloric acid or potassium hydroxide. The ceramic solution and chemicals react to form an agglomeration or network that becomes increasingly viscous (thick). With enough time and heat, the solution fully gels and hardens. Heat isn’t always necessary, it just speeds up the process.

To produce ceramic-coated cookware, manufacturers create this ceramic solution and spray or dip the pan to coat it before the sol-gel hardens. Once it hardens, the surface is essentially the same as a regular ceramic, just with metal underneath.

Conventional ceramic is made with silica, clay, and other minerals, meaning sol-gel ceramic isn’t strictly ceramic but is fairly similar.

The beauty of sol-gel processing is that manufacturers can be certain of what is in the coating. The process also significantly reduces how much energy is needed to produce cookware. In most cases, the coating doesn’t have to be cured at high heat. For aluminum coated pans, high heat is actually detrimental anyway.

Is sol-gel ceramic-coated cookware safe?

The short answer is… maybe.

The sol-gel chemical process isn’t inherently toxic (and is actually pretty eco-friendly!). However, ceramic coatings can contain any number of metals or elements. These include lead and cadmium, both of which are toxic heavy metals, and titanium dioxide nanoparticles, which may harm health if absorbed.

The (potential) trouble with titanium dioxide

Titanium dioxide (TiO2) is legal in the U.S. and the United Kingdom. The European Union banned titanium dioxide as a food additive on August 7, 2022. However, that decision was overturned in court in November, 2022.

The initial ban was based on the European Food Safety Authority’s concerns that TiO2 absorbed from food may be genotoxic and could cause cancer. There isn’t currently enough evidence, though, to support the claim of genotoxicity. In fact, the EU’s classification of TiO2 as carcinogenic was based on one unreliable study, which is why the ban was overturned. In response, the Center for Science in the Public Interest (CSPI) advised consumers to avoid food products containing TiO2.

Note, too, that this ban was for TiO2 in food. That is, TiO2 as a food additive, such as in Skittles. The use of the chemical in cookware was never banned, with no evidence to show that it poses a risk to human health. We do have concerns, based in reliable evidence, that aerosolized TiO2, such as in sunscreens, is best avoided as it can be inhaled and damage the lungs.

Caraway Home doesn’t explicitly state that its cookware is free of titanium dioxide. Instead, it is one of the few cookware brands to offer third-party testing for the presence of some heavy metals (lead and cadmium) and for heavy metal leaching (including titanium). These brands are far and away your best choice if you’re keen to buy ceramic non-stick cookware. If a company is not transparent about its testing (or doesn’t do any), stay away.

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Why do some tests seem to show heavy metals in Caraway Home cookware?

We dug into Caraway Home’s claims more fully because several readers asked us about the tests carried out by an independent researcher (Tamara Rubin). These raise concerns that the cookware does, in fact, test positive for heavy metals.

Full disclosure: I’m not a materials scientist or chemical engineer, nor am I certified in X-Ray Fluorescence (XRF) technology or able to carry out these kinds of tests myself. I don’t have a $50,000 XRF spectrometer at home, alas.

We don’t know the exact test conditions for Rubin’s tests. We assume, though, that Rubin has the best of intentions to help inform consumers suspicious of Caraway Home’s claims. Our main worry is that XRF testing is not necessarily reliable for this kind of product, especially as done using a handheld device on used cookware.

Potential problems with XRF testing of cookware

XRF has, like any test, certain detection limits for heavy metals. In the case of titanium and cobalt, this can be around 250 parts per million, while lead can have a detection limit of around 50 ppm. The detection limits vary depending on the sample and how it is prepared. The length of the sampling process also matters.

The Consumer Product Safety Commission (CPSC) considers XRF testing reliable for use in testing for lead in paint. This is in large part because paint is a homogenous substance. For metal cookware with a thin surface coating, XRF may not be suitable, however.

In fact, for aluminum cookware, it may be particularly problematic. This is because XRF testing is not effective for elements with an atomic number less than 16. This includes aluminum (atomic number 13). The presence of aluminum (and sulfur and silicon!) can cause interference with the results for other metals. This seems especially relevant in a pan made with an aluminum core and a relatively thin surface coating. Ideally, any XRF tests would be of the ceramic coating only, as provided by the manufacturer or scraped off an unused product.

In practice, XRF analysis is limited by these interference effects among elements. This can render some elements “invisible” to the detector and make others impossible to accurately quantify. The limits of detection vary greatly between elements. Arsenic is often masked by lead, for instance, while chromium levels often appear higher at the expense of iron.

It’s great that Rubin carried out three periods of sampling, up to 120 seconds for the surface coating of the Caraway pan. However, the very low levels of lead reported in Rubin’s tests (14-51 ppm) seem to be quite close to potential detection limits. This could mean the readings are actually a reporting error.

For titanium, the levels detected by Rubin are much more pronounced. This suggests either significant contamination of the test material or that Caraway Home uses titanium dioxide in its sol-gel coating. Without further testing, or full disclosure from Caraway Home, we can’t know if titanium is part of the ceramic coating. The company’s third-party tests do, however, show no detectable titanium leaching from the pans.

Surface smoothness and contamination concerns

Contamination is another confounding factor when testing used cookware. Such contamination could come from oil, food, and utensils. Rubin tested a used pan sent to her by a consumer. We don’t have a photo of the pan, but the sense is that the coating was cracked and stained. XRF professionals consistently highlight a clean test surface as key for accurate results.

Though oil itself usually won’t interfere with test results, Caraway pans can be used with metal and silicon utensils. This may leave traces of metal and silicon on the cook-surface. Similarly, certain foods are actually fairly high in lead. These include meat (especially offal), fish (including seafood), vegetables (especially sweet potatoes and carrots), and cereals. Cookware may also become contaminated with lead from household dust or other objects.

It’s possible, then, that used cookware (especially with surface staining) could test positive for heavy metals even if the pan itself doesn’t contain lead, cadmium, and so forth. The condition of the test surface can also affect the results of XRF testing.

Which tests can we believe?

Caraway Home voluntarily tests its cookware using third-party laboratories. It runs tests for PTFE, lead and cadmium, as well as tests for leaching of these and other toxic metals. The tests are done by SGS and use the same methods as the U.S. Food and Drug Administration.

One of the tests is known as CPSC-CH-E1003-09.1 and looks for lead in surface coatings, such as in paint and on children’s toys. This kind of analysis involves scraping off the surface coating and dissolving it in an acidic solution to allow for analysis. The test occurs under strict laboratory conditions with sterile equipment to minimize contamination.

Arguably, this is more accurate as a way to detect lead and other heavy metals than using a handheld XRF device that can only assess the top layer of a surface coating (which may be contaminated from external sources). Detection limits are also higher for coatings that are less than 5 mm thick, which may include the coating on Caraway pans.

It’s also worth noting that XRF devices have to operate at a certain voltage to provide accurate results for cadmium and antimony, among other things. The RoHS WEEE (Restriction of Hazardous Substances Directive and Waste Electrical and Electronic Equipment Directive) standard also calls for a testing time of several minutes to properly detect cadmium and lead in metal alloys

Caraway also undertakes LFGB testing, which stands for Lebensmittel-, Bedarfsgegenstände- und Futtermittelgesetzbuch, AKA the German abbreviation for the German Food and Commodities Act. Materials that come in contact with food are subject to this piece of German legislation and must be tested for PFOA and certain toxic metals, including lead, cadmium, mercury, etc.

Want to know more about XRF testing? Here’s a nice little webinar slide show!

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The verdict – is Caraway Home guilty of greenwashing?

From the information available, it appears that Caraway Home is at risk of greenwashing, but we just don’t have enough information. What we can say for sure is that there’s serious room for improvement in its marketing. The way the company phrases certain claims could be considered misleading to the average consumer. The results of independent tests also suggest the company may use TiO2 without disclosing this to customers, which is problematic even if Caraway Home doesn’t consider this to be toxic (which, to be fair, is also the position of food safety regulators in the U.S., EU, and UK).

As things stand, there’s no evidence that Caraway cookware will leach toxic heavy metals into food. In fact, there’s robust evidence that the ceramic coating doesn’t leach heavy metals and doesn’t contain lead or cadmium. For us, certified laboratory testing carries greater weight than handheld XRF testing of used cookware by one (albeit well-intentioned and well-regarded!) researcher.

Next steps for Caraway Home and consumers

What I’d like to see going forward is a full list of the materials and processes Caraway Home uses to make it pots, pans, and bakeware. This would help clear up any confusion over the presence of certain metals, rather than just whether they leach from the product. And, if it turns out the company does use titanium dioxide as a component of its sol-gel, letting consumers know this would allow for a more informed choice.

It would also be great to see Caraway test its products prior to shipping. Assuming the company’s raw materials are free of things like lead, cadmium, and mercury, the presence of these in the final product would alert the company that some contamination has occurred along the way. That might mean checking machinery, chemicals and solvents, and even packaging and storage procedures.

In the meantime, we stand behind our recommendation that Caraway Home remains one of the best options for a non-stick, non-toxic pan that, if used properly and cared for, could last several years. Given that ceramic coatings degrade, though, the more sustainable, safer choices are cast iron or carbon steel cookware. Season these right and they’re almost non-stick. They also last for generations. Stainless steel is another good option, while pure ceramic is a top choice for bakeware.

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  1. This paragraph worries me.

    There is a chance that Caraway Home uses titanium dioxide nanoparticles to make the sol-gel. However, third-party tests show no detectable titanium leaching from the surface coating when exposed to an acidic solution at 100 degrees Celsius for two hours (twice). Similarly, the tests show no detectable level of mercury, cadmium, cobalt, lead, or other toxic or potentially toxic metals in two or three rounds of tests (lead and cadmium testing).

    Why would they do lab test at only simmer temps of an electric stovetop. They should be testing for high setting at like 400c . Not everyone wants to wait 30 minutes for their eggs to cook.

  2. Thank you so much for such an informative article about Caraway products. So many companies are trying to find a “safer” version of non-stick. As for me, I think I’ll just “stick” to the tried and true stainless steel and cast iron workhorses which continue to be the safest choices!

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