Is 304 stainless steel always food grade?
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304 stainless steel is one of the most widely used materials in food containers, cookware, water bottles, and kitchen equipment. But is all 304 stainless steel truly food grade? The short answer is no-not every piece of 304 stainless steel automatically meets food safety standards.
Understanding what makes stainless steel "food grade" is essential for manufacturers, suppliers, and consumers alike.
"304" and "316" are designations assigned by the American Iron and Steel Institute (AISI). In China, the national standard GB/T 221-2008: Designation of Steels classifies stainless steel based on its carbon content and other alloying elements.
For example, 304 stainless steel is referred to as 06Cr19Ni10, where "06" means the carbon content is no more than 0.08%, and "Cr19" and "Ni10" indicate the chromium and nickel contents.
316 stainless steel typically refers to 316L, designated in China as 022Cr17Ni12Mo2 (formerly 00Cr17Ni14Mo2), with "Mo" indicating a higher molybdenum content. This element improves the steel's corrosion resistance-especially in chloride-containing environments such as seawater and saline solutions-making it more corrosion-resistant than 304.
Table 1 Requirements for Heavy Metal Content in Metallic Substrates and Coatings
| Metal Substrate and Coating | Heavy Metal Element | Content (Mass Fraction)/% |
|---|---|---|
| Stainless Steel | Arsenic (As) | ≤ 0.01 |
| Cadmium (Cd) | ≤ 0.01 | |
| Lead (Pb) | ≤ 0.01 |
Table 3 Migration Limits of Heavy Metal Elements
| Item | Limit Value (mg/kg) | Test Method |
|---|---|---|
| Arsenic (As)* | ≤ 0.002 | GB 31604.49 |
| Cadmium (Cd) | ≤ 0.002 | GB 31604.49 |
| Lead (Pb) | ≤ 0.01 | GB 31604.49 |
| Antimony (Sb) | ≤ 0.04 | GB 31604.49 |
* For iron-based enamel products without lead glaze, the limit for arsenic is 0.018 mg/kg.
China's national standard GB 4806.9-2023: Food Safety Standard for Metal Materials and Articles in Contact with Food clearly defines the limits for impurities and the migration of alloying elements in stainless steel materials. Only stainless steel that passes the tests specified in this standard can be considered food-grade.
Therefore, even if a batch of 304 stainless steel fails the migration test of metallic elements, it cannot be used for food containers. When purchasing stainless steel tableware or cups, it is recommended to check whether the product complies with GB 4806.9-2023. If it does and comes with a valid certificate of conformity, it is safe for food contact.
Looking for certified food-grade stainless steel?
GNEE Stainless Steel offers fully traceable, GB 4806.9-2023 compliant 304 and 316L stainless steel with surface finishes optimized for food safety and hygiene.
✅ Custom grades & specifications
✅ Third-party migration test reports
✅ Precision polishing for low surface roughness
Contact us now to request samples or a quote.
