Clay pots have been used throughout civilization, with archaeological evidence showing proof of their use by Egyptians, Romans, and Greeks. Later, metal cookware like cast iron, stainless steel, and non-stick was introduced. However, with this coated cookware came safety concerns about toxic materials like PTFE coating and acid reactions that can cause serious health problems. But is earthen cookware safe?

This article explains in detail the safety of clay pots and answers questions like whether pottery clay contains lead and how it affects cookware. It also covers what can contribute to chemical leaching and how to prevent it. Read it to the end to learn more. But let’s first find out about the different clay pots.

Different Types of Clay Pots

Below are the different types you will find when purchasing clay cookware.

●  Glazed clay pots: are clay cookware coated with non-toxic glaze material such as kaolin or feldspar, creating a non-stick surface. This feature makes glazed clay pots ideal for various cooking methods and is easy to clean. They are safe cookware because they are non-porous, but only if the glaze is free from toxic substances. The glazed pottery’s firing process melts the minerals forming an impervious surface.

●  Unglazed clay pots: Unglazed clay cookware is made from natural clay and has no coating. The surface of these pure clay pots is porous, making them ideal for cooking food that needs slow cooking, like beans, as they keep the food moist.

However, cooking food in this pot can affect its flavor due to its porous nature. These pots are also fragile, making them prone to cracking, and they include types like traditional Mexican pots.

●  Tagines: clay or ceramic cookware of North African origin used in cooking beans, stew, or slow-cooked dishes. Their distinctive conical shape allows steam circulation when cooking moist and tender food.  

Clay Pot

What Science Says About Clay Cookware

100% pure primary clay contains minerals like magnesium and calcium, which are essential for bone health. Other minerals include silica, which is necessary for healthy skin and nails, and iron, which helps with red blood cell production. However, this type of clay for cooking pots contains traces of arsenic, lead, or cadmium.

Nevertheless, clay pots are included in the healthy cookware discussion, especially if made with high-quality primary soil. This is according to scientific research such as Miriam’s earthen cookware test report. The test evaluated different aspects of safety and effectiveness. Below are some of the test areas:

●  Lead and Cadmium levels: Miriam’s earthen cookware carried out this test to ensure that the clay pots are free from lead, cadmium, and any other harmful elements that can leach into food cooked using the cookware. The test result showed that the MEC pots were below the permissible levels of these metals.

●  Chemical leaching: The company also tested for leaching while cooking specific foods. From the test, acidic and basic foods cooked in the MEC pots didn’t have traces of chemicals.

●  Heat retention: On heat retention, the test proved that clay cooking pots have good heat retention. Additionally, they have even heat distribution, which enables even cooking.

However, it is noteworthy that the safety of these pots depends on the clay’s type and quality. When buying your glazed or unglazed clay pot, you should be cautious and choose the food-safe ones. 

Below is a table showing the effects of acetate-contaminated food cooked in non-clay cookware on multiple organs.

ParametersLiver (g)Kidney (g)Brain (g)Spleen (g)Testis (g)Heart (g)
Group1 negative control3.30 ± 0.240.74 ± 0.040.87 ± 0.070.41 ± 0.041.46 ± 0.270.46 ± 0.05
 Group 2 L1Pb3.53 ± 0.25*0.88 ± 0.080.74 ± 0.110.45 ± 0.06*1.84 ± 0.17*0.38 ± 0.03*
 Group 2 L2Pb3.90 ± 0.28*0.84 ± 0.120.87 ± 0.050.64 ± 0.16*2.03 ± 0.33*0.36 ± 0.03*
p valuep < 0.05No sign.No sign.p < 0.05p < 0.05p < 0.05

Is Earthen Cookware Safe?

In general, clay cookware is safe for cooking and serving food. However, some may contain lead, depending on the type of clay used and features like glazing. So, do clay pots leach chemicals? Yes, clay pots can leach chemicals such as arsenic and other heavy metals.

The leaching happens if the primary clay used contains the chemicals. In addition, a poorly formulated glaze can contribute to the leach. Therefore, it’d be best to check if the primary clay used to make the pot has been tested for heavy metals and if it is lead-free before buying it.

Clay pots are safer than metal cookware, which can release toxic fumes when heated. People are usually exposed to potentially toxic material in their cookware daily. However, knowing the factors contributing to chemical leaching during clay pot cooking would be best.

Clay Cookware

Factors that Contribute to Chemical Ieach

Here are some factors contributing to the leaching problem and how to avoid them:

Clay Quality

When the clay cooking pot comes into contact with alkaline or acidic food, the poor-quality clay contributes to the leaching issue. The food will interact with the clay, leading to food contamination. To avoid such earthen cookware, you should look for pots made from pure primary clay sourced from within the earth, to which no toxins are added during the making process. It will also help to check for FDA certification.


Glazing, which makes clay pots usable on kitchen appliances like stove tops, can contribute to chemical leaching. This problem arises when the glaze isn’t food-safe. Choose pots with a red shade of fired clay labeled food-safe or unglazed clay cooking pots to avert this problem. In addition, you should avoid using a cracked or broken clay pot.

High Heat and Extended Cooking Time

High temperatures and extended clay pot cooking times also contribute to chemical leaching. Exposing the clay pot to sudden or high-temperature changes leads to expansion and contraction. The changes caused by high heat form cracks and fissures from which the chemical will leach.

Furthermore, cooking for an extended duration may contribute to leaching, especially in acidic foods like tomato sauce. To avoid this, cook on low to medium heat and use a timer when cooking acidic food. It will also help to season the cookware by soaking it in water for about 30 minutes.

Cleaning and Maintenance

How you clean and maintain your cooking pots also contributes to this problem. Harsh abrasive cleaning agents can create cracks where the toxic minerals will leach into the food. Failure to rinse the unglazed earthenware can leave detergent residue on the porous surface, leading to food contamination.

To prevent this, you should avoid using abrasive cleaning agents. Instead, use warm water and rinse well when washing. Although clay cookware is dishwasher-safe on a gentle cycle, you should do it by hand to prevent chipping or cracking.

Clay Pot

Why You Should Choose Clay Pot Cooking

Cooking in an unglazed earthenware pot made from natural clay has several benefits besides the low risk of toxic metals contaminating your food. Here are some of the reasons why you should cook food in a clay pot:

Enhanced Nutrient Retention

Food preparation in healthy cookware, like unglazed pots, enhances nutritional value by retaining moisture during cooking. And this happens due to the cookware’s porous nature, which enables steam cooking, allowing your food to cook in natural juices. As a result, it will be flavorful and nutritious, making it ideal for cooking food for people with specific dietary restrictions and promoting healthy eating.

Reduced Oil Usage

Clay pot cooking also reduces oil usage due to its natural non-stick features. Thanks to its porous nature, food preparation is slow and doesn’t require excessive oil use. This feature makes clay pot cooking the best if dietary restrictions limit your fat intake.

Improved Digestion

Cooking your food in unglazed clay cookware also improves digestion. For starters, the pots made from pure primary clay have no toxic metals, making them safe to cook in without risk of digestive problems. In addition, the clay in such pots is alkaline, helping to neutralize food acidity. Slow cooking also makes food easy to digest. As a result, you will reduce the chances of gut inflammation.

Energy Efficiency and Eco-Friendly

Unlike metal cookware, clay pots are energy efficient as they distribute heat evenly when cooking. The cooking process takes less heat, and the food remains warm after you are done. This feature also reduces cooking time, saving time.

 In addition, clay pots are made from natural, biodegradable, and renewable materials, making them eco-friendly.


1.   How do you know if clay has lead in it?

Using baking soda, you can tell if your pot’s clay contains lead. Mix a tablespoon of baking soda in a cup of water, then boil the solution for about five minutes. You will then let the solution cool before using it to test, with pink or red discoloration meaning the presence of the heavy metals.

2.   Is it safe to drink water from clay pots?

Drinking water from earthenware is safe, provided it is from pure clay pots, because they are free from toxic materials. However, ensure you clean the pot properly before storing drinking water. You should also replace the water often to prevent bacteria growth, which will impurify the water.

3.   Are Mexican clay pots safe to drink from?

Mexican clay pots are safe to drink and made from 100% pure primary clay. However, not all glazes are safe because some potters use toxic substances. You should ensure you purchase clay cookware like these pots from reputable sellers.

4.   How do I know if my Mexican pottery is lead-free?

Determining if your Mexican unglazed clay pot is lead-free requires a testing swab kit available online or in hardware stores. To test it, you will rub the swab on the pot’s surface and observe any color change. Alternatively, you can use baking soda, as you learned earlier.


It is no secret that the use of clay pots is on the rise in the wake of health concerns. But is clay cookware safe? It is safe to say that, like ceramic cookware, clay pots are safe, provided they are made from the purest form of clay.

Unlike metal cookware, which reacts and chemically binds to the food you are cooking with heat acting as a catalyst, clay pots made from natural materials don’t have this problem.

Therefore, it will help to use the information you have read here as you purchase clay cookware from reputable companies that test for the complete composition.


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