What Is Stainless Steel? A Plain Guide to Grades, Safety and Food Use
Stainless steel is in your kitchen, your kids' plates, and your water bottle. But not all stainless steel is the same. Here is what actually matters: the grades, what they contain, and why it is the material we built Greenvyne around.
What Is Stainless Steel Made Of?
Stainless steel is a metal alloy made primarily of iron and at least 10.5% chromium. That chromium content is what makes it 'stainless': it reacts with oxygen to form a thin, stable oxide layer on the surface that resists rust and corrosion. Unlike plain steel, this layer is self-repairing. If the surface is scratched, it reforms on its own.
Depending on the grade, other elements are added: nickel for corrosion resistance and strength, molybdenum for performance in harsh or acidic conditions, and manganese or carbon to fine-tune hardness.
Around 60% of new stainless steel is made from recycled material. It is one of the most recycled metals in the world and can be melted down and remade without any loss of quality.
Stainless Steel Grades Explained: 304, 316 and 430
The grade tells you what is in the alloy and how it will perform. For kitchenware, three grades come up most often.
|
Grade |
Also called |
Composition |
Best for |
Greenvyne use |
|
304 |
18/8 |
18% chromium, 8% nickel |
Everyday food contact, durability |
Plates, bowls, cups |
|
316 |
18/10 or marine grade |
16% chromium, 10% nickel, 2% molybdenum |
Acidic foods, high-use items, and medical |
Cutlery, future water bottle range |
|
430 |
18/0 or ferritic |
16% chromium, no nickel |
Nickel allergy, bakeware |
Bakeware and decorative items |
The number system (18/8, 18/10) simply reflects the chromium and nickel percentages in the alloy. Both 304 and 316 are food-grade and widely used in commercial kitchens, medical equipment, and food manufacturing. For most families, 304 is the practical standard. All Greenvyne products are independently lab tested to LFGB and EU 10/2011 standards. See our testing standards →
Is Stainless Steel Safe for Food Contact?
Food-grade stainless steel (grades 304 and 316) is non-porous, which means bacteria cannot embed in the surface the way they can in plastic or wood. It does not absorb odours or flavours, and it does not require coatings or linings that could break down over time.
Unlike many plastics, stainless steel does not contain BPA, phthalates, or other endocrine-disrupting chemicals. It does not leach these compounds into food or drink, regardless of temperature or acidity.
That is the core reason we chose it for Greenvyne. The material does not need to be in perfect conditions to be safe. It works the same way on day one as it does years later.
Nickel in Stainless Steel: What You Need to Know
Grades 304 and 316 contain nickel. For the vast majority of people, this presents no issue. Nickel occurs naturally in many foods, including oats, nuts, legumes, and leafy greens, and the body processes dietary nickel as part of normal function.
A small percentage of people have a nickel sensitivity or contact allergy. Symptoms are usually localised skin reactions from prolonged direct skin contact with nickel-containing metals, rather than from food contact or ingestion.
Research on nickel migration from stainless steel into food shows that trace amounts can occur, particularly when cooking acidic foods (such as tomatoes or citrus) for extended periods. The quantities involved are generally well within food safety thresholds, but individuals with confirmed nickel allergies may prefer to use grade 430, which contains no nickel.
If you have a diagnosed nickel allergy, speak with your healthcare provider about what is appropriate for your situation.
Is Stainless Steel Sustainable?
Stainless steel has a strong sustainability case, though it is worth being clear about what that means.
Recyclability. Stainless steel is 100% recyclable and can be remade repeatedly without degrading in quality. Approximately 60% of new stainless steel production uses recycled content.
Longevity. A well-made stainless steel item can last decades. Fewer replacements means less manufacturing, less waste, and less consumption overall.
No coatings to degrade. Non-stick coatings, lacquers, and plastic linings can chip, flake, or break down. Stainless steel does not require them. There is no coating to replace or to shed into food.
The environmental cost of production is real. Stainless steel requires significant energy and raw materials to manufacture. The sustainability argument rests on longevity: the longer a product lasts, the more its production footprint is justified.
Why We Use It at Greenvyne
When we were developing the Greenvyne range, we looked at every material used in kitchenware: plastics of various grades, silicone, glass, bamboo composites, titanium and stainless steel. The question was simple: what material requires the fewest compromises when it comes to safety, sustainability, durability, and practical everyday use?
Stainless steel answered that question consistently. It does not leach synthetic chemicals. It does not degrade with heat or repeated washing. It holds up in a family kitchen, a school lunchbox, a camping bag, without needing special handling and can truly last a lifetime.
It is also the material standard in commercial food service and medical settings, which tells you something about how it performs at scale and under scrutiny.
If you are thinking about switching away from plastic, our guide on why stainless steel outperforms plastic for kids' tableware is a practical starting point.
Happy Steeling,
-Vee
Greenvyne
DISCLAIMER
The information in this post is for general educational purposes only. It is not medical or professional advice. If you have specific health concerns, including a nickel allergy or other sensitivities, consult a healthcare professional. Individual experiences may vary.
