What Cookware Is Toxic, and What Is Safe?

how to choose safe, non-toxic cookware

“What Cookware Should I Use?”

It’s a question I receive often.

With all the available choices today in cookware, there seems to be many varying opinions as to which type of cookware is truly safe. As much as we emphasize on a clean diet, it is equally important to realize that the choice of cookware can also make a huge difference because they contain chemicals that can leach into the food.

Here’s how the different kinds of cookware stack up – if you’d like to consult with a leading functional medicine doctor in Singapore, please get in touch.

Is Glass Cookware and Drinkware Safe and Non-Toxic?

Yes, glass if completely safe for food and drink. Glass is generally inert, or non-reactive, and it is also non-leaching and is impermeable to liquids and gases. However, there are certain type of glass that have toxic lead or cadmium in them, and they can leach into food or drink. For example, lead glass containers or lead crystal glasses, or glasses with glazes can be toxic, to a certain extent.

In summary, glass is completely safe as long as you avoid lead glass and lead crystalware.

Is Ceramic Cookware Safe and Non-Toxic?

Generally speaking ceramic dishes are perfectly safe as long as any glazes are free of lead and cadmium. Ceramic dishes are categorized into traditional and advanced/technical. The traditional ceramics are mostly earthenware, pottery dishes and artistic creations. These are made up of Kaolin (clay), quartz, feldspar and cement. The advanced versions of ceramic cookware use aluminum oxides, silion carbide and more.

Ceramics are usually chemical, heat, acid and corrosion-resistant. Like glass, ceramics are generally inert and safe. One concern could be the glazes used on ceramic, as there is the possibility of it containing toxic lead or cadmium. This is unlikely with ceramics made in Europe and North America for food use, but if unsure, check with the manufacturer. S

How Safe are Stainless Steel Pots and Pans?

As the name suggests, stainless steel should stain ‘less’ and not corrode (i.e., not rust). That said, it’s not totally stain free. It is normally thought of as being corrosion-resistant. However, this depends on the grade and quality of the steel.

The base element is iron, and to this Chromium is added, which makes it corrosion resistant. Carbon is further added in small amounts to increase its strength and hardness.  Nickel is sometimes added to stabilize this structure and to increase integrity to high temperature extremes and corrosion resistance. Other metals that are added include molybdenum and titanium.

Stainless Steel Grades

Food grade stainless steel pots and pans are in the 304 Series. They are designated as either 18-8 or 18-10. The ’18’ refers to the percentage of chromium in the stainless steel, and the ‘8’ or ’10’ the percentage of nickel. Both are high quality stainless steels. The chromium and nickel are what make stainless steel corrosion-resistant, increased strength, durability. Nickel also gives the cookware a measure of temperature resistance.

Stainless steel grades with very little nickel do exist (e.g., grade 430) and cost less, but they are considered lower quality because of their decreased corrosion and temperature resistance. Similarly, there are other grades with low nickel content (e.g., grades 201 & 202), in which the nickel is replaced by more manganese. Manganese is significantly less expensive than nickel, but the resulting stainless steel may be slightly more susceptible to corrosion in certain circumstances and may have a slightly inferior surface appearance. The nickel content also may be increased, creating a slightly higher grade stainless steel. For example, grades 316 and 317 may have 10-15% nickel content and include molybdenum, the combination of which increases resistance to specific forms of corrosion in extreme environments.

So Are Stainless Steel Pans Safe?

Common food grade stainless steel (18-8 or 18-10, 300 series) can release trace amounts of certain elements – but the higher the quality of the stainless steel, the less the leaching. There are four key possibilities for release from 300 grade stainless steel: iron, chromium, manganese and nickel.

1. Iron: Majority of the population need iron and the amounts released do not cause toxicity. In very high iron overload individuals, it is best to alternate with other options.

2. Chromium: Like iron, can also be positive for human health in small doses. The safe intake range is around 50 to 200 micrograms per day and 1 meal prepared from them might release 45 micrograms of Chromium, which is well within safe levels. Even eating with stainless steel dishes several times a day is fine, as less chromium is released from just eating off the dishes compared with cooking in them using heat. Remember, that if the stainless steel is of high quality it will be stable and very little if any will be released. And any releases through normal wear and tear of high quality stainless steel should be miniscule at most.

Stainless steel does not contain hexavalent chromium, which is a highly toxic carcinogen.

3. Manganese: The uptake of manganese by humans mainly takes place through food, such as spinach, tea and herbs. As such, the trace amounts leached amount from wear and tear is miniscule and equals the amounts taken through food on daily basis.

4.Nickel: It is not toxic in small amounts, but it can provoke a reaction in people with allergies or sensitivities to nickel. Small amounts of nickel can be transferred from stainless steel containers or cookware to foods – especially when the food in question is acidic (e.g., tomatoes, rhubarb).
The amounts of nickel that may be released from non-corrosive stainless steel products – oatmeal, nuts & almonds, and fresh & dried legumes, all of which have a relatively high nickel content. That said, if someone suspects s/he may have an allergy to nickel or show high nickel amounts through tests, choose the less nickel content grade of steel or avoid completely.

In summary, stainless steel is a safe material for use in everyday life, including for items such as food containers, dishes, cookware, utensils, water bottles and dispensers. If you have a nickel allergy, avoid stainless steel, or try only 200 grade (nickel-free) stainless steel.

If you use enameled steel, make sure it’s a good quality (Claud, Salad Masters, and All-Clad are all good brands if affordable).

Is Aluminum Cookware Safe To Use?

Aluminum is not necessarily safe for use in cookware. There is increasing evidence and testimonials about the prevalence and dangers of aluminum poisoning. There are documented adverse human health effects that can result from aluminum exposure, including neurotoxicity, Alzheimers, breast cancer and mitochondrial dysfunction.

Annodysed aluminum have become a popular alternative. The anodizing process “locks in” the aluminum, but anodization can break down over time.

Suggestion: Avoid all aluminum cookware, including anodized aluminum ones.

How Safe Are Cast Iron Skillets For Use in Cooking?

Cast iron is essentially pure iron that has been heated and then poured into a mold to create a particular form. Carbon and silicone are key alloying elements that are added to the pure iron to increase its strength and malleability.

Cast iron cookware will release iron into the food being prepared, but this is not necessarily a bad thing (only if you have an iron allergy or suffer from iron overload). In fact, the use of cast iron cookware is considered a safe way to maintain and increase ones dietary iron intake, and is even considered a way of reducing iron deficiency. The amount of iron released from cast iron cookware will depend on the food, its acidity and water content, how long it was cooked and how old the cookware is. More will be released from newer cookware used to cook acidic food (apples, tomato sauces or Indian dishes).

If you use an enameled cast iron, choose the ones with good quality enamel, like Le Creuset or Staub brands.

For personal use, I prefer to use vintage 50s-era cast iron cookware, because the nickel content is much lower. All things considered, cast iron is safe to cook with.

Is Copper Cookware Safe?

Copper cookware can be safe, but take precautions. It’s best to avoid copper, as the coating tends to degrade over time, leading to more exposure. Copper is an essential element for many enzyme reactions, and thus necessary for the body at low levels as a dietary mineral contributing to good health. If you have copper water pipes and your water is soft (often the case in Singapore), then substantial copper may be leaching from the pipes into the water through corrosion. One way to overcome this is to simply let the water run for a bit (15-30 seconds) in the morning to pass through the water that has been sitting in the pipes (and brass fixtures if you have them) all night.

Exposure to excess copper can also occur with the use of uncoated copper cookware, especially when acidic food that is in contact with the copper. Most copper cookware is coated with another metal, but this protective layer can degrade over time when used extensively with acidic food and/or scoured with steel wool.

Other Common Cooking Materials:


Titanium is considered to be safe, but we do not yet have enough information and data to make a strong decision.

Tin and Brass Cookware

Avoid tin and brass cookware – they contain lead and other toxins that will pass through to your food.

Is Non-Stick Cookware, Like Teflon, Safe?

No, you should ditch your Teflon cookware immediately. Most nonstick cookware are aluminum coated with polytetrafluoroetheylene (PTFE), which is well known to be toxic.

If you have any questions about cookware, feel free to contact Dr. Radhika Kamat. She is a well-known gastro doctor in Singapore, and she approaches medicine from a naturopathic, and sometimes homeopathic, perspective. She always works to find the  root cause of a patient’s symptoms, and whether they are related to auto-immune disease, diet, stress, or something else, she would be happy to help.

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