Is Carbon Steel Non-Toxic?

As I strive to make clean and nutritious meals for my family, I prioritize using quality, non-toxic cookware. Choosing non-toxic cookware plays a crucial role in maintaining our overall health. As a researcher, I know the materials used in pots and pans can leach harmful substances into food, potentially affecting long-term well-being. Similarly, as more people become aware of the potential risks associated with traditional non-stick cookware, they are shifting towards safer alternatives.

As you may know, professional kitchens frequently select carbon steel cookware for its durability, versatility, and high heat tolerance. Unlike non-stick pans that can degrade over time, carbon steel builds a natural layer of seasoning, improving its performance with use. This post explores whether carbon steel is non-toxic to human health and the environment, helping you make an informed decision about your cookware choices.

Is Carbon Steel Non-Toxic?

Understanding carbon steel helps determine its safety as a cookware option. This section covers what carbon steel is, its composition, and its benefits compared to other cookware materials.

What Is Carbon Steel And What Is Carbon Steel Made Of?

Interestingly, carbon steel cookware functions like a hybrid between a cast iron skillet and stainless steel pan. It shares the durability and natural non-stick layer of seasoning of a cast iron pan but offers a smoother surface and is lighter weight, making it easier to handle. Like stainless steel, carbon steel heats up quickly and responds well to temperature changes.

Specifically, carbon steel consists of 99% iron and 1% carbon. In comparison, cast iron pans are approximately 97% iron and 3% carbon. Since carbon steel contains less carbon, it weighs less and is less brittle than a cast iron skillet (source).

More specifically, manufacturers produce this cookware from large sheets of carbon steel. They then cut, press, and form the steel into fry pans, woks, and other cookware shapes. Manufacturers often strengthen the pan and improve heat distribution by subjecting it to a heat treatment process. This process results in two main varieties—blue steel and black steel. After shaping, manufacturers usually coat or pre-season the pan with oil to protect it against rust and prepare it for use (source).

What Is Carbon Steel Used For?

To begin, chefs favor carbon steel for its excellent heat conductivity. This property makes it ideal for high-heat cooking like searing, stir-frying, and sautéing. Additionally, it develops a natural non-stick surface once seasoned, which is perfect for delicate foods like eggs and fish.

Furthermore, carbon steel is a top choice for wok cooking due to its responsiveness to heat. It also excels in heat retention for crispy textures and perfect crusts. Lastly, chefs often prefer carbon steel grills for outdoor cooking as they quickly heat up and maintain heat well (source).

Is Carbon Steel Safe For Health?

The good news is, yes, carbon steel is considered a non-toxic cookware material. Moreover, carbon steel cookware provides an enticing alternative to non-stick pans. We know by now that most non-stick pans sold in stores are made using PFAS chemicals. I believe it is only a matter of time before further legislation restricts the use of these concerning “forever” chemicals.

With that said, let’s explore the safety considerations when using carbon steel cookware. In my review, carbon steel is a safe cooking material. However, in 2024, one brand came under scrutiny in France, which I will discuss next.

Matfer 2024 Recall

In April 2024, the Direction Départementale de la Protection des Populations (DDPP) of Isère ordered French brand Matfer to recall particular fry pans from its carbon steel cookware line. The DDPP exposed Matfer pans to a boiling acidic solution for two hours and found that they leached certain concerning metals at levels exceeding the European Union’s strict safety limits (source). For your convenience, I have included a list of recall lot numbers.

Remarkably, Matfer appealed the recall, disputing the test parameters. Furthermore, the company asserts that all its carbon steel pans are made from materials that comply with the strict EU food contact safety standards. According to Matfer, the DDPP conducted the test on an unseasoned pan using a highly acidic solution—conditions that do not reflect typical use. In fact, Matfer argues that this approach acted outside of the scope of proper testing and compromised the validity of the results (source).

At this point, regulators are still reviewing the appeal, and no pans have been recalled outside of the EU. Keep in mind that all cookware has safety considerations when misused or subjected to conditions beyond its intended purpose. Indeed, as you’ll read further, acidic foods are not suitable for cooking in carbon cookware. Yet, out of an abundance of caution, until the Matfer appeal is reviewed, I am not recommending Matfer fry pans. 

How To Cook With Carbon Steel

Cooking with carbon steel pans is very similar to cast iron. Below I will cover important tips when using your carbon steel pan so you can walk away prepared to use your skillet for years to come. Let’s look into:

• seasoning a carbon steel pan
• preheating and adding oil
• avoiding acidic foods, and
• cleaning and maintenance.

Seasoning A Carbon Steel Pan

Before using a new carbon steel pan, you must season it to build up a natural non-stick surface and protect it from rust. First, gently clean the pan with warm, soapy water to remove any factory wax or contaminants from shipping.

Second, after drying it thoroughly, apply a thin layer of oil, such as raw food-grade flaxseed (linseed) oil, to the entire surface of the pan. Next, place the pan on the stovetop or in the oven at a high temperature, around 400-450°F (200-230°C), and let it heat for about 1-2 hours.

During this process, the oil undergoes polymerization, a chemical reaction that bonds the oil to the pan, forming a hard, protective layer. This layer not only helps prevent rust but also creates the base for the non-stick coating.

Once the pan cools down, wipe away any excess oil and repeat the process several times to create a durable seasoning. Over time, the seasoning improves and deepens, resulting in a smooth, darkened surface. Regular cooking with oil will continue to enhance the seasoning, making the pan more non-stick and resistant to damage (source).

Preheat And Add Oil

Carbon steel is particularly well-suited for high-heat cooking, allowing you to sear meats, stir-fry vegetables, and achieve professional-level results that require quick and even heat distribution. However, to get the best performance, it’s crucial to preheat the pan for a few minutes before cooking.

Preheating ensures that the entire surface reaches the desired temperature. Simply heat the empty pan over medium heat for 2-3 minutes before adding your cooking oil and other ingredients.

When cooking with carbon steel, always use a small amount of cooking oil to help maintain the seasoned surface. The oil prevents sticking and helps sustain the protective layer that has developed over time. Using a cooking oil with a high smoke point, like avocado oil, prevents the oil from burning or smoking at high temperatures.

While carbon steel excels at medium and high-heat applications, cooking at very high heat with too little oil can cause the pan to warp or the seasoning to break down, leaving the pan vulnerable to rust and food sticking. By using oil and controlling the temperature, you can maintain the integrity of the seasoning and keep your carbon steel pan performing at its best for years (source).

Avoid Acidic Foods

Cooking is very similar with cast iron and carbon steel. If you have ever cooked with cast iron, you know that certain foods can wear away the seasoning you have created on your pan. Cooking acidic foods, such as tomatoes and citrus-based sauces, can degrade the seasoning of the pan. A well-seasoned pan can handle mild pH fluctuations, but predominantly acidic sauces and foods will strip away the built-on seasoning.

To preserve the seasoning, cook acidic dishes containing tomatoes, vinegar, or lemon juice in glass, stainless steel, or enameled cookware. This avoids the need to start the initial seasoning process over again. Learn more about other cookware brands I recommend in my blog post Safe Cookware Guide That Makes Sense.

Cleaning And Maintenance

For starters, never soak carbon steel cookware in water. Instead, use hot water and a scrub brush to clean it immediately after cooking. Avoid dish soap, as it can strip away the seasoning. Don’t forget, the job of a good dish soap is to attract and loosen grease, which is what the seasoning is made up of.

After washing, dry the pan thoroughly, then use a cloth or paper towel to apply a very thin coat of oil to maintain its protective layer. While this may seem high maintenance, in reality, a well-seasoned pan cleans easily, and this process becomes routine.

Once again, carbon steel cookware offers an excellent non-toxic alternative to traditional non-stick pans. Furthermore, carbon steel is an impressive alternative to the popular ceramic-coated cookware. Ceramic-coated cookware has its own safety considerations, which I discuss in my post Is Ceramic Cookware Safe?.

Carbon Steel Recommendations

As carbon steel cookware has gained popularity, more brands have become available. Each offers different sizes and weight considerations. Take a look at the brands I selected in my Amazon shop. You will find they are generally less expensive than stainless steel pans! For your convenience, I have included silicone handle covers as well.  

Furthermore, I made sure to include pans from the French brand de Buyer. In a third-party XRF test on two of their carbon steel pans, the food contact surfaces were ‘non-detect’ for non-dietary metals (source). In other words, they contained only iron and manganese, both of which are minerals used by our bodies.

Conclusion: What Is So Special About Carbon Steel Cookware?

Carbon Steel Is A Versatile, Non-Toxic Material, And Lighter Weight Than Cast Iron. With A Proper Seasoning, It Performs Well In High Heat Cooking And Maintains A Naturally Non-Stick Finish.

To sum up, home cooks and chefs choose carbon steel as a non-toxic cookware option that outperforms traditional alternatives when properly maintained. Unlike synthetic non-stick coatings that deteriorate and release potentially harmful chemicals, carbon steel naturally builds a protective layer of seasoning. Moreover, this seasoning enhances its non-stick properties over time.

With regular use, a well-seasoned pan becomes even more effective, making it a kitchen staple for years. Additionally, carbon steel withstands high heat, ensuring better cooking results without the risks associated with Teflon-coated cookware.

The primary care instructions advise against using acidic foods on carbon steel, as they can strip away the protective seasoning. By preheating the pan and applying oil, the seasoning should continue to improve with age. Maintenance is simple – scrub with hot water, dry, and apply a thin coat of oil with a rag or paper towel. If you avoid soaking and dish soap, both the pan and seasoning should last for years.

By following proper care and maintenance, you can enjoy the benefits of carbon steel cookware while avoiding unnecessary toxins in your meals. Investing in carbon steel means prioritizing both health and cooking performance for a lifetime of safer, more enjoyable home cooking.

Take advantage of the I Read Labels For You blog for the latest research on living toxic-free and browse my shop and my Amazon shop for non-toxic products. Schedule a consultation for help with making the switch to a toxin-free lifestyle and get access to my unique e-books.

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