Is 310 Stainless Steel Food Grade?

What Does Food Grade Mean for Stainless Steel?

Food grade is not a metallurgical property written into a material standard; it is a compliance result. A stainless steel is accepted for food contact when the finished article passes migration tests defined by the applicable regulation, such as GB 4806.9 in China, Regulation EC 1935/2004 in the European Union or FDA 21 CFR 177 in the United States. The decisive parameters are the release of heavy metals into food simulants, mainly lead, chromium and nickel, and the surface condition of the finished article. Under GB 4806.9, the migration limits for stainless steel food-contact articles include Pb ≤0.01 mg/kg, Cr ≤0.4 mg/kg and Ni ≤0.5 mg/kg, with the test typically performed in 4% acetic acid food simulant at defined time and temperature.

Composition of 310 and 310S

310 and 310S are high-chromium, high-nickel austenitic grades. 310S is the low-carbon version with a carbon maximum of 0.08%, while 310 permits up to 0.25% carbon. The grade contains no molybdenum requirement; its very high nickel content is the main point of attention for food-contact qualification.

Element	ASTM A240 310, UNS S31000	ASTM A240 310S, UNS S31008	EN 1.4845 X8CrNi25-21
C	≤0.25%	≤0.08%	≤0.08%
Si	≤1.50%	≤1.50%	≤1.50%
Mn	≤2.00%	≤2.00%	≤2.00%
P	≤0.045%	≤0.045%	≤0.045%
S	≤0.030%	≤0.030%	≤0.015%
Cr	24.0-26.0%	24.0-26.0%	24.0-26.0%
Ni	19.0-22.0%	19.0-22.0%	19.0-22.0%

Can 310 Pass Food-Contact Requirements?

In principle, yes. Because 310 and 310S release very low amounts of lead and chromium, and because nickel migration in 4% acetic acid is normally well below 0.5 mg/kg in short-duration, low-temperature contact, articles made from these grades can comply with GB 4806.9 limits. The outcome, however, depends on the food simulant, temperature, contact time and finish of the article, and must be demonstrated by laboratory test reports rather than assumed from the grade name.

310 vs 304 and 316L for Food Equipment

Property	304, 1.4301	316L, 1.4404	310S, 1.4845
Nickel content	8.0-10.5%	10.0-13.0%	19.0-22.0%
Molybdenum	none	2.0-3.0%	none
Relative cost	low	medium	high
Typical max service temperature	≈870°C	≈800°C	≈1050°C
Typical food use	tanks, conveyors, cutlery, kitchen equipment	dairy, brewing, acidic food, brine handling	ovens, fryers, baking trays, high-temperature processing

Applications of 310 in the Food Industry

310 and 310S earn their place in food processing where temperatures exceed the capability of 304 and 316L: bakery and confectionery ovens, frying and roasting equipment, baking trays and racks, heat exchangers for hot oil, retort and pasteurization systems, and combustion or exhaust components of food processing plants. For ambient-temperature contact with food, 304 or 316L is the economic and equally compliant choice.

Frequently Asked Questions

Is 310 stainless steel food grade?

310 and 310S can comply with food-contact migration limits such as GB 4806.9 in many applications, but compliance must be verified by migration test reports for the specific article, food simulant and contact conditions.

What is the difference between 310 and 310S for food use?

310S limits carbon to 0.08% maximum, which avoids chromium-carbide precipitation during welding and is the preferred variant for welded food equipment.

Does 310 release nickel into food?

Nickel migration depends on food acidity, temperature, contact time and surface finish. In standard tests such as GB 4806.9, migration must remain below 0.5 mg/kg; acidic hot food increases the release rate, which is why 304 and 316L are preferred for acidic products.

Why is 304 more common than 310 in food equipment?

304 provides sufficient corrosion resistance and strength for the great majority of food-contact applications at lower alloy cost, while 310 is specified only where service temperatures exceed about 870°C.

Which standard governs food-contact stainless steel in China?

GB 4806.9 sets the safety requirements and migration limits for stainless steel and other metal materials intended for food contact.

Can 310 be used for cookware such as pots and pans?

Technically it can, but it is oversized and uneconomical for that purpose; 304 and 316L are the standard grades for cookware, subject to the food-contact regulation of the destination market.