Industry News

Can a stainless steel kettle be used? Now I finally figured it out!

Food and metallurgical experts said in an interview with Xinhua News Agency that qualified hot water bottles would not harm human health, and pointed out that the Jiangsu Quality Supervision Department sampled 4% acetic acid as a food simulant.
On the morning of the 29th, the Jiangsu Bureau of Quality Supervision responded to the "2016 Electric Kettle Product Risk Monitoring Quality Analysis Report" released on the 17th, saying that it was a quality random inspection and risk monitoring work carried out in accordance with the deployment of higher-level departments. The details of the test such as "food simulants" did not give a reply.

Is there any harm to the human nervous system when boiling water in a stainless steel kettle? Is there any problem with the inspection by the authority? With doubts, the reporter launched an investigation.

The origin of the storm: a "discussion" triggered by an electric kettle quality inspection report

The reporter combed and found that the web post started with the "2016 Electric Kettle Product Risk Monitoring Quality Analysis Report" issued by the Jiangsu Provincial Quality Supervision Bureau on March 17. In the first paragraph of the report, it was pointed out that the main problem found during the random inspection was "the manganese content of 55.6% of electric kettle products is about 10%, and there is a problem with the use of high manganese steel."

The report also pointed out that this time 45 batches were tested for manganese precipitation, of which 25 batches were made of high manganese steel, mostly unknown brands, reflecting the fact that electric kettle product manufacturers are choosing stainless steel for the kettle body. Sometimes there is a phenomenon of lax checks, and low-cost high-manganese steel is used to pursue benefits and reduce costs.

Then, on 19th and 20th, in a TV station column in Guangdong Province, a doctor said that food containers made of "high manganese steel" would cause "manganese" to dissolve when heated, and said that long-term excessive intake Manganese can damage the human body. Various local media and websites have also reported, saying that "stainless steel hot water boiling water is harmful to human health, and there is a risk of carcinogenesis and stupidity."

Beginning on the 21st, countless WeChat public accounts and online media began to "frequently exert force", and the "toxic hot water bottle" incident continued to ferment: series of articles with keywords such as "think carefully" and "drink this water to become silly and cause cancer". The Internet is flooded, and the kettle made of "high manganese steel" has also been officially transformed into a "poison kettle".

Many netizens have turned from waiting and watching to fear, and even citizens continue to join the "kettle-throwing" team.

Are there any problems with the test? Is high manganese steel harmful to the human body?

The content of manganese in a 55.6% stainless steel kettle is as high as 10%. How is the conclusion of this test drawn?

The reporter studied this test report and found that the food simulant used in the test was 4% acetic acid food simulant instead of daily water. It is obviously a pot for boiling water, why use 4% acetic acid food simulant for testing?

Ye Nengsheng, associate professor of the Department of Chemistry, Capital Normal University, pointed out that in this Jiangsu quality inspection report, the food simulant used "4% acetic acid food simulant." According to the "National Standard of the People's Republic of China GB31604.1-2015" issued by the National Health and Family Planning Commission, it is specified in the "Selection of Food Simulants" in the "National Food Safety Standard-General Rules for the Migration Test of Food Contact Materials and Products" Requirement, "When the food contact material is non-acidic food (PH>=5) in water-based food, the food simulant should be 10% (volume fraction) ethanol or water." Ye Nengsheng said, measuring heat with 4% acetic acid The content of manganese in the raw material of the kettle will be higher than the result of the test with water. If testing an electric kettle that is only used for boiling water, testing liquid water is the correct testing method, and choosing different food simulants may affect the accuracy of the test results.

The reporter asked why the "water" required by the national standard was not used as the test liquid, but 4% acetic acid food simulant liquid was used for testing. The Jiangsu Provincial Quality Supervision Bureau did not respond. As for the manganese content in the raw materials of the hot water kettle sold on the market, we still need to wait for more accurate and authoritative test results.

Many metallurgical experts said in an interview with reporters that the "stainless steel kettle" sold on the market does not rule out the phenomenon of containing high manganese steel, but even so, qualified stainless steel electric kettles will not harm human health.

According to the "Reference Intake of Dietary Nutrients for Chinese Residents" compiled by the Chinese Nutrition Society, adults are recommended to consume 3.5 mg of manganese per day, and the maximum tolerable intake is 10 mg per day, that is, a lifetime intake of 10 mg per day. Will cause health hazards.

According to Chen Xinliang, Director of the Office of the China Iron and Steel Association, from a professional point of view, qualified stainless steel products are heated to a temperature of 100 degrees Celsius when the water boils, and it is impossible to precipitate excessive manganese. At the same time, even if there are heavy metal elements in the boiling water, there is no human body. Metal digestive enzymes cannot absorb the manganese in the raw materials of the kettle. Moreover, the toxicity of manganese is much lower than that of lead, arsenic, cadmium, nickel and other elements. The clinically seen patients with manganese poisoning are mostly caused by the respiratory system and most of them are caused by occupational reasons. Manganese poisoning caused by eating is very rare.

Ye Nengsheng analyzed from the perspective of food safety. He said that manganese is an essential trace element for the human body, and many enzymes are activated by this element. If the manganese content in the daily food intake of the human body is not excessive, it will not threaten health.

Experts Weapon Selection of "Safe Pots" The people hope that the authoritative monitoring report will be more accurate. The "Poison Kettle Incident" aroused public concern about the safety of drinking water and the choice of household cooking utensils. Wang Chengwen, a citizen of Xicheng District, Beijing, said that he has not used electric kettles to boil water for two consecutive weeks.

In this regard, Chen Xinliang and other metallurgical experts introduced that from the perspective of food safety, the selection of a qualified kettle is a necessary condition. How to select "qualified" stainless steel kettles? Pay attention to the words "GB 9684" on the inner and outer walls of the container first. If there is this mark, it means that the container meets the national standards for stainless steel products.

At the same time, Chen Xinliang also recommends that consumers bring their own "magnets" when buying stainless steel products for verification: Put the magnets close to the tested cookware. Anything with suction (including weak suction) can basically be regarded as unqualified stainless steel.

For consumers who have higher requirements for quality of life, Chen Xinliang suggests that the current 300 series (including the 304 steel widely promoted by the media) and 400 series stainless steels are high-quality stainless steels, and their production processes are complex, and both performance and cleaning performance are good. Excellent, it is recommended to choose.

Wang Chengwen and other citizens interviewed said that after a period of time, reports concerning the safety of utensils and food and drinking water will be spread wildly on the Internet. These "kind reminders" also add a lot of trouble to life. The people attach great importance to the monitoring of authoritative departments and look forward to more accurate and complete monitoring reports.

In this regard, Ye Nengsheng and other experts and industry insiders suggested that the issuing agency of the quality inspection report and the authoritative department should conduct inspections in a standardized manner, such as accurate selection of food simulants. At the same time, third-party institutions with testing qualifications (such as the physical and chemical analysis testing center) can play the role of "supervisor" and exert influence and effect in dispelling rumors. In addition, media communication should strive to be rational, research and then speak out, so as not to cause panic among the public.