What is food grade stainless steel?

Food grade stainless steel refers to the stainless steel material in accordance with the "National Standard of the people's Republic of China / hygienic Standard for stainless Steel tableware containers" GB 964-88. 

Its lead and chromium content is much lower than that of ordinary stainless steel.

Index regulation:

Food grade stainless steel refers to the part of food machinery in contact with food, which must meet the requirements of certain food safety. Because the food production process to use a lot of acids and bases, and stainless steel containing chromium, unqualified stainless steel, will dissolve all kinds of chromium, toxic; and require to limit the content of lead, cadmium and other alloy impurities.

Difference between Food Grade stainless Steel and 304 stainless Steel:

When the amount of heavy metals transported in stainless steel products exceeds the limit, it may be harmful to human health.

Therefore, the production of stainless steel cooking utensils needs to find a balance between corrosion protection and safety. If the content of nickel and chromium is high, the anti-corrosion function is enhanced, but the precipitation of nickel and chromium will also increase, which means the increase of safety risk.

Because of this, the national standard of food safety of "stainless steel products" (GB9684-2011) has made strict regulations on the precipitation index of chromium, cadmium, nickel, lead and other heavy metals in cooking utensils.

Why does the national standard not stipulate the migration limit of manganese?

 One reason is that with the increase of manganese content in stainless steel, accompanied by the loss of corrosion resistance, non-rust and other functions of cooking utensils, once the manganese content is high to a certain value, the product can not be used as cooking utensils or can not be called stainless steel cookers. But even such high levels of manganese generally have no effect on health.

Therefore, although the national standard of food safety does not stipulate the content of manganese, it is clearly pointed out that the main part of food containers must be made of stainless steel materials in accordance with the national standards.

 

Food grade stainless steel is stainless steel that conforms to GB9684 standard.

Food grade stainless steel, also known as "GB9864 stainless steel", is the stainless steel material specified in GB 964 / 2011 in the National Standard of the people's Republic of China / hygienic Standard for stainless Steel tableware containers. The "lead" content of this stainless steel is much lower than that of ordinary stainless steel, and the anticorrosion property of the product is also increased. It is required that lead (in terms of Pb), mg/L 4% acetic acid immersion solution ≤ 1.0. Chromium (calculated by Cr), mg/L 4% acetic acid immersion solution ≤ 0.5. Nickel (calculated by Ni), mg/L 4% acetic acid immersion solution ≤ 3.01.0. Tin (in terms of Sn), mg/L in 4% acetic acid solution ≤ 0.002. Arsenic (in terms of As), ≤ 0.004 in mg/L 4% acetic acid solution. Note: the soaking conditions were boiling for 30 minutes and then at room temperature for 24 hours.

304 stainless steel is a very common stainless steel, also known as 18-8 stainless steel in the industry. Its corrosion resistance is better than 430 stainless iron, corrosion resistance and high temperature resistance, good processing performance, so it is widely used in industrial and furniture decoration industry and food and medical industry, such as: some high-grade stainless steel tableware, bathroom kitchen utensils.

304 is a kind of universal stainless steel, which is widely used in the manufacture of equipment and parts that require good comprehensive properties (corrosion resistance and formability).

In order to maintain the inherent corrosion resistance of stainless steel, steel must contain more than 17% chromium and more than 8% nickel.

General 304 stainless steel is not food grade, specially processed is food grade.

It is well known that 304 and 316 stainless steel must be used in stainless steel products related to "edible". 316 stainless steel prices are high, mostly used in high-end equipment, such as aerospace, food machinery and other fields. The food grade stainless steel used in daily necessities, most of which is 304 stainless steel, has good acid resistance and strong corrosion resistance.

In contrast, 201 and 202 stainless steel (commonly known as high manganese steel) are generally used in industrial products and cannot be used as tableware because they:

Nickel content is not up to standard, acid and alkali resistance is poor, easy to rust;

Excessive manganese content, excessive intake of manganese in the human body will lead to nervous system damage.

To distinguish these different stainless steel materials, the main method in the laboratory is to detect the composition of the substance, different materials of stainless steel, there will be obvious differences in metal composition. For ordinary consumers, this method is too professional and unsuitable, and the most appropriate is to use 304 manganese content measuring reagent, just drop on the surface to be able to detect whether the manganese content exceeds the standard. Thus, 201 stainless steel and 304 stainless steel can be distinguished, while the difference between ordinary 304 stainless steel and food grade stainless steel needs to be distinguished by more detailed laboratory tests. But we need to know that the composition of food-grade stainless steel is the most stringent, while industrial stainless steel is much simpler.

Generally speaking, food grade stainless steel refers to stainless steel that conforms to the national GB9684 standard certification and can really come into contact with food without causing physical harm. GB9864 stainless steel is the stainless steel material that conforms to the national GB9684 standard certification. So GB9864 stainless steel is food grade stainless steel. At the same time, the so-called 304 stainless steel does not require to be certified by the national GB9684 standard, 304 stainless steel is not equal to food grade stainless steel, 304 stainless steel is not only used in kitchen utensils, but also widely used in industry, the harm to human body is unknown. At the time of purchase, regular goods will be marked with "food grade 304stainless steel" on the surface and inside of the product, while products marked "food grade-GB9684" will be safer.