Food-grade stainless steel is a highly corrosion-resistant, non-reactive, and non-toxic metal material suitable for various food contact applications. Its main advantages include high heat resistance, easy cleaning, high strength, and the absence of harmful metal leaching, making it widely used in cutlery, cookware, kitchen equipment, and food production facilities.
Whether in China, the United States, or Europe, the standards for food-grade stainless steel aim to ensure that it does not pose a health risk when in contact with food and maintains food safety and purity.
This article will introduce food grade stainless steel from many aspects, as well as some common food grade stainless steels.
What is Food-Grade Stainless Steel?
Food-grade stainless steel refers to a metal material that meets specific safety standards and can safely come into contact with food. It typically has the following characteristics:
Corrosion Resistance: Food-grade stainless steel is highly resistant to corrosion, preventing rust and other chemical reactions during long-term use. This makes it suitable for environments that require constant contact with food and beverages.
Non-Reactive Surface: Stainless steel is a non-reactive metal, meaning it does not react with acidic or alkaline foods. Other metals, such as aluminum or iron, may react with acidic foods, affecting taste and damaging the metal surface.
No Harmful Substance Migration: Food-grade stainless steel does not release harmful chemicals into food and complies with strict migration limits. This is crucial because harmful elements in stainless steel (like chromium, nickel, lead, etc.) can pose health risks if they leach into food.
Standards and Regulations for Food-Grade Stainless Steel
Chinese Standard (GB4806.9-2016)
This standard limits the migration of heavy metals such as arsenic, cadmium, lead, chromium, and nickel when metal materials are in contact with food. Testing involves heating stainless steel containers with food simulants (such as 4% acetic acid solution) and checking for metal migration.
U.S. Standards (NSF and FDA)
Stainless steel must contain at least 16% chromium. Chromium helps improve corrosion resistance and prevents rust and bacterial growth. While chromium is beneficial in small amounts, excessive intake can be harmful.
European Standards
Although there is no unified chromium content standard in Europe, clear requirements exist for metal release testing. Stainless steel is exposed to acidic solutions, and the metal release is tested to ensure safety.
Why is Stainless Steel Used for Food?
Heat Resistance and Corrosion Resistance
Stainless steel can withstand extreme temperatures and acidic environments. Its oxide layer prevents rust and contamination, making it ideal for kitchen equipment, tableware, storage equipment, etc.
Easy to Clean
Stainless steel has a smooth surface that resists bacteria and dirt buildup, making it easy to clean. In contrast, materials like wood or plastic can accumulate bacteria in grooves and seams.
Strength and Durability
Food-grade stainless steel is very strong and durable. Even with long-term use, it maintains stable performance, reducing the need for frequent replacements and lowering maintenance costs.
Non-Toxicity
Food-grade stainless steel is a non-reactive metal that will not release harmful substances into food, ensuring food purity. Other materials, especially under high temperature and acidity, may affect food taste or cause contamination, but stainless steel is much more stable.
Impact on Human Health
The small amounts of nickel and chromium in stainless steel typically do not pose a health risk. In fact, these elements can be beneficial to human health in moderation (e.g., chromium helps with glucose metabolism). However, if the stainless steel cookware is scratched or worn down, it could release some nickel or chromium. Proper maintenance of stainless steel cookware is essential to avoid such issues.
What Types of Stainless Steel Are Food-Grade?
Stainless steel is classified into different series based on its composition and properties. Food-grade stainless steel is commonly found in specific types within the 200, 300, and 400 series. Each type has a different content of chromium, nickel, and other elements, which gives them distinct properties suitable for various food contact environments.
Here are the most common types of food-grade stainless steel:
200 Series Stainless Steel
200 series (such as 201 and 202) replace nickel with manganese to lower production costs. This makes them easier to process but reduces their corrosion resistance, making them prone to rust. While these steels can be used for food contact, they are not high-quality and are not recommended for long-term food contact.
Common types: 201, 202
Advantages: Lower cost
Disadvantages: Poor corrosion resistance, prone to rust
The 300 series is the most commonly used high-quality stainless steel in the food industry. It includes 304 and 316 types, both offering excellent corrosion resistance and are suitable for food processing and storage environments.
304 Stainless Steel (18/8)
304 is the most commonly used food-grade stainless steel, with 18% chromium and 8% nickel. It has good corrosion resistance, is easy to clean, and has good welding performance. It is the preferred material for most kitchen equipment, food storage, and processing equipment.
Common uses: Tableware, cookware, kitchen equipment, storage tanks, refrigeration equipment, etc.
Advantages: Resistant to most acidic substances, easy to clean
Disadvantages: Susceptible to salt corrosion, suitable for low-salt environments
316 Stainless Steel (18/10)
316 stainless steel has an additional 2% molybdenum, making it more corrosion-resistant, especially in chloride solutions. It is widely used in marine environments, chemical processing, and medical fields. Though 316 stainless steel is more expensive, it is ideal for environments with stringent corrosion resistance requirements.
Common uses: Marine equipment, biomedical implants, high-corrosion environments (e.g., seawater, chemicals)
Advantages: Very high corrosion resistance, suitable for harsh environments
Disadvantages: Higher cost
The 400 series is magnetic stainless steel and usually does not contain nickel, which makes it less corrosion-resistant but harder. It is suitable for specific food contact applications.
430 Stainless Steel (18/0)
430 stainless steel contains approximately 18% chromium and negligible nickel. It is not as corrosion-resistant as 304 and 316, and it can rust easily and lose its shine. It is commonly used for low-cost food contact applications, such as kitchen decorative items and some tableware.
Common uses: Tableware, kitchen decorations, stove surfaces
Advantages: Lower cost, magnetic
Disadvantages: Poor corrosion resistance, prone to losing shine
440 Stainless Steel
440 stainless steel has high hardness and wear resistance, making it ideal for kitchen knives and cutting tools. However, its corrosion resistance is poor, so it is not suitable for tableware or food containers.
Common uses: Kitchen knives, cutting tools
Advantages: High hardness, wear-resistant
Disadvantages: Prone to rust, not suitable for tableware
What is the Best Food-Grade Stainless Steel?
Overall, depending on the application environment, different types of stainless steel may be the best choice:
- 304 Stainless Steel (18/8): Most commonly used, suitable for general food contact and kitchen equipment.
- 316 Stainless Steel (18/10): Has better corrosion resistance, ideal for high-salt, high-corrosion environments.
- 430 Stainless Steel (18/0): Lower cost but poor corrosion resistance, suitable for low-cost applications.
- 440 Stainless Steel: High hardness, ideal for kitchen knives, not suitable for tableware.
For food industry applications, 304 and 316 stainless steels are the most common and best choices, as they offer high corrosion resistance, strength, and ease of cleaning, meeting the safety requirements for food contact.
How Can Manek Help
At Manek, we offer our clients a series of customized services specifically for stainless steel and other metals, including investment casting, sand casting, die casting, CNC machining, sheet metal fabrication as well as various surface treatments.
We also provide a variety of other manufacturing capabilities. You can get quotations for free, such as 3D printing, plastic injection molding and powder coating.
