Behind the cheap items labeled "304 stainless steel" or "316 stainless steel" flooding e-commerce platforms and sidewalks lurks a danger that many people have never considered.
There are many ways to distinguish low-quality stainless steel products (Illustrative image: Getty).
Stainless steel kitchenware, from bowls and chopsticks to pots, pans, and woks, is present in most Vietnamese kitchens thanks to its high durability, light weight, resistance to breakage, and ease of cleaning.
However, behind the cheap items labeled "304 stainless steel" or "316 stainless steel" that are widely available on e-commerce platforms or sold on sidewalks, there are hidden risks that not all consumers are aware of.
A recent survey by Hubei Radio and Television, China, in collaboration with independent testing units, revealed an alarming situation: up to 70% of stainless steel products sold online are counterfeit.
Out of 20 randomly selected bowls and plates advertised as 304 or 316 stainless steel for testing, 14 failed to meet the standards. The majority of these products were actually made from 201 or 410 steel, with only a very thin layer of stainless steel coating to deceive consumers.
The dangers behind the ultra-thin stainless steel layer.
According to Dr. Vu Thi Tan, lecturer in Inorganic Chemistry Technology, School of Chemistry and Life Sciences , Hanoi University of Science and Technology, 201 and 410 steels typically contain high levels of manganese, while the proportions of chromium and nickel are much lower than those found in food-grade stainless steel.
Dr. Vu Thi Tan, lecturer in Inorganic Chemical Technology, School of Chemistry and Life Sciences, Hanoi University of Science and Technology (Photo: Hoa Le).
To deceive buyers, some manufacturers employ a multi-layer plating technique, in which the core is made of cheap steel, and the outside is coated with a very thin layer of stainless steel.
Essentially, these are steel items coated with stainless steel. When exposed to high temperatures, strong detergents, or frequent scrubbing, this coating gradually peels off. At that point, the metal elements in the steel core begin to leach into the surrounding environment, Dr. Tan explained.
Under normal cooking conditions, especially with foods heated above 100°C or acidic dishes like sour soups, pickled vegetables, lemon sauce, vinegar, or salty foods, the surface structure of the metal is easily damaged. The stainless steel plating disappears, revealing the steel core inside.
Metals such as nickel, manganese, titanium, vanadium, chromium, silicon, molybdenum, tungsten, and cobalt can be released directly into food.
More dangerously, many counterfeit stainless steel products can still pass common tests. When a stainless steel testing solution is dropped onto the surface, the outer plating does not turn red, leading buyers to mistakenly believe the product meets standards, when in reality only the outer shell is being tested.
After some use and cleaning, the plating gradually wears off, exposing the lower-quality core, which then begins to rust.
Furthermore, instead of clearly stamping the steel code like SUS304 or SUS316, the packaging of these products often only states "high quality stainless steel," making it difficult to trace the origin and evade legal responsibility.
Tips for identifying low-quality stainless steel at home.
According to Dr. Vu Thi Tan, consumers should not rely on a single test but should combine multiple indicators.
First and foremost, prioritize products with clearly embossed SUS304 or SUS316 material codes on the body or bottom. Products with only general markings often pose a higher risk.
Technically, 304 and 316 stainless steel belong to the austenitic group, meaning they are almost non-magnetic. If a magnet strongly attracts the material in multiple locations, especially the sides and rim of the pot, it is likely an alloyed steel or 410 steel. However, since the processing can create slight magnetism, this test is only for initial screening.
Another way to test is to try it on an induction cooktop. If the product is advertised as solid 304 or 316 stainless steel but the induction cooktop still heats the entire body, users should question the material. This method should rule out multi-layered stainless steel pots and pans specifically designed for induction cooktops.
According to Dr. Tan, products with thin stainless steel plating often reveal their poor quality very quickly when put in a dishwasher. If, after a short time, the utensils become tarnished, stained, or show rust spots, it is a sign of low-quality stainless steel.
Advice for consumers
Dr. Vu Thi Tan advises consumers to prioritize products from reputable brands, purchase them from authorized distributors, and avoid products priced significantly lower than the market average.
Foods that are acidic or salty should not be stored overnight in stainless steel containers. In these cases, ceramic or heat-resistant glass containers are a safer option.
Stainless steel cookware can be a great help in the kitchen, but only if it's genuine stainless steel. With low-quality, counterfeit products, consumers need to be cautious, as the health of their entire family may be silently compromised.