Eating self-heating hot pot triggers an alarm! Even after eating, it may explode？
CCTV News recently reported on the safety investigation of self-heating hot pot.
You don’t need fire or electricity, just add a bottle of water, and you can enjoy the hot pot … … Nowadays, the so-called "lazy people cook their own hot pot" has quietly become popular, and some brands have also introduced self-heating foods such as rice, noodles and vermicelli. However, in the investigation, the reporter found that although the self-heating convenient hot pot is delicious and fast, there are certain safety hazards. The heating package of self-heating food is flammable and explosive, so consumers should be very careful when using it, and it is not allowed to take it by train or plane.
What is a self-heating hotpot?
Self-heating hot pot does not need fire or plug in electricity, and it is mainly composed of ingredients, an ingredient pot, a pot cover, an outer pot and a heating bag. The heating principle is to use the substance in the heating bag to contact with water to release heat, so that the temperature of the food in the upper food pot increases after absorbing heat. Besides self-heating chafing dish, it is also called micro chafing dish, clear boiled chafing dish and self-cooking chafing dish.
This product, which first appeared in Wechat business’s circle of friends, attracted more and more catering and food companies to join. From making hot pot bottom materials to chain hot pot restaurants, many companies have started self-heating small hot pot business. Even a good shop that makes snacks sells self-heating hot pot in its own Tmall flagship store. Now go to e-commerce platforms such as Tmall and JD.COM to search for "self-heating hot pot", and at least nearly 30 brands will appear.
Eat a hot pot and call the police!
However, there is no small safety risk in this convenient hot food. The reporter noticed that there are many reports on the Internet that the alarm will give an alarm when the self-heating hot pot is used, and consumers have sent the video that triggered the continuous alarm of the gas alarm when using the self-heating hot pot to the short video platform.
Consumer Xiao Chen has been afraid to eat self-heating hot pot at home since it caused the gas alarm to call the police. According to reports, she was operating in the kitchen according to the instructions. After the lid began to steam, she planned to go back to the house for a while, but before she left the kitchen, the gas alarm suddenly rang.
"At that time, I was shocked. I was afraid of gas leakage and specially called the gas company. The other party said that the gas did not leak after the door-to-door inspection." The inspectors said that it may be caused by the self-heating chafing dish, because the gas alarm will only give an alarm when it detects that carbon monoxide exceeds the standard, which may be caused by the gas released when the self-heating chafing dish is heated.
In addition, consumer Xiao Li told reporters that once he ate self-heating rice on the glass coffee table at home, the vent hole on the lid of the box just burst, and he heard a bang, and the corner of the glass coffee table burst, causing the rice to spill all over the floor.
The reporter bought a box of self-heating hot pot at random. After unpacking, first put the hot pot bottom and all the ingredients into the lunch box and add cold water. Then tear off the outer bag of the heating package and put it in the bottom box, and add cold water without heating the package. Place the food box on the heating bag, open the vent hole on the closed cover and cover the hot pot tightly. After a few seconds, steam will be ejected from the vent hole. After a few minutes, the sound of boiling water will be heard in the box, and the box will expand and deform when heated, and the high temperature can be felt near the lunch box. After more than 10 minutes, the box gave out a bang, and then the gas alarm at the reporter’s home rang. Turn off the gas alarm and wait for a few minutes, open the airtight cover, and high-temperature steam will blow on my face. In the process of eating, the self-heating hot pot has always maintained a high temperature. After eating for an hour, the outside of the lunch box still feels hot.
The manufacturer said this.
Why does the alarm continue to alarm?
So, what is the reason that causes the gas alarm to alarm continuously? The reporter dialed the telephone number of the manufacturer of the heating package. "When the heating package heats up, it will produce a small amount of hydrogen, because hydrogen will cause the smoke sensor to alarm." The person in charge of a heating package manufacturer said. Hydrogen is a combustible and reducing gas. Pure hydrogen burns quietly in the air, while impure hydrogen may explode when it burns.
Is it dangerous to generate hydrogen in the heating package?
However, in view of the hydrogen generated during the reaction of the heating package, the personnel of the manufacturer claimed to the reporter that "there is absolutely no safety hazard".
The person in charge of a heating package manufacturer told the reporter: "It doesn’t matter. If that thing is dangerous, it can’t be so hot in the market. Don’t think it’s so dangerous, it’s not so dangerous, and big companies are doing it."
safety test
1 In a confined space, the heating package has the risk of deflagration.
The manufacturer of the heating package said that there was absolutely no potential safety hazard. However, reports about the alarm of the self-heating food appeared from time to time. Then, is there a safety hazard after the heating package reacts with water?
Not long ago, the Shanghai Consumer Protection Committee informed about the testing of 20 self-heating instant hot pot products. The test items include the inspection of appearance and packaging label, the surface temperature of the pot, the gas released by the heating package when it meets water, the secondary water addition reaction of the heating package, the composition and content of the heating package and other indicators. The test results show that all the tested heating packages belong to "substances or mixtures that emit flammable gases when in contact with water".
Shang Zhaocong, executive deputy director of the National Chemical Product Safety Quality Inspection Center, told the reporter: "We have done a lot of experiments, and basically each heating package can generate about 40 liters of hydrogen. The combustion limit of hydrogen in air is 4% to 75.6%. Of course, there are other closed or semi-closed conditions, such as inside the car, which will have similar risks. "
You should also be careful when eating hot pot together on the tourist bus.
Not only the self-heating food may bring the risk of deflagration when it is used in a closed space, but also it has great safety hazards when it is used intensively in some public places.
Xiao Qiuping, assistant director of the National Chemical Products Safety Quality Inspection Center, said: "For example, many tourists don’t know that hydrogen will be generated during the driving of tourist buses and long-distance buses. The large-scale use of self-heating hot pot may lead to the accumulation of hydrogen in vehicles, especially in summer, when the air conditioner is turned on, and the whole compartment is in a closed environment. In this case, if the lower explosion limit concentration is reached and a little fire source is encountered, a lighter is not needed.
3 After using the discarded heating package, there are still potential safety hazards.
Experts also told reporters that not only the self-heating products may bring the risk of deflagration after reaching the deflagration limit value of hydrogen in the use process, but also there are safety hazards after using the discarded heating packages.
In this experiment, the Shanghai Consumer Protection Committee also submerged 20 sample heating packages in water again. The results show that there are 14 samples of heating packs with different degrees of continuous deflation. The reaction duration is more than 3 minutes, and the longest is 8 minutes.
If such a heating package is discarded and meets water in a closed space such as a garbage can, and a little fire source is added, it may burn.
Safety warning to be standardized, safety standards to be issued.
In terms of product standards, there are currently no national and industrial standards related to self-heating instant hot pot products and heating packages in China. In fact, this unpredictable but possible security risk needs to be clearly reminded before users use it. However, the reporter found that at present, no self-heating product on the market has made a clear warning against these problems.
Cai En, director of the Consumer Guidance Department of the Shanghai Consumer Rights Protection Committee, said: "The manufacturer of heating packs should first make further tests and analysis on the components and related proportions of its heating packs, including the weight, to ensure that this heating pack can fully respond and ensure the safety of consumers when using it."
In this test, 18 samples of heating packages were marked with main components and corresponding enterprise standard codes. According to the marked main components, it can be divided into two groups: group ⅰ is calcium oxide, aluminum particles and sodium bicarbonate; Group II is calcium oxide, aluminum powder, sodium carbonate and sodium hydroxide. The heating packages of the other two self-heating instant hot pot samples were not marked with ingredients and enterprise standard codes.
According to the Catalogue of Hazardous Chemicals (2015 Edition) issued by state administration of work safety and other ten ministries and commissions, "aluminum powder" belongs to hazardous chemicals. In the list of dangerous goods in the United Nations Model Regulations on the Transport of Dangerous Goods, "uncoated" aluminum powder belongs to the listed 4.3 substances that release flammable gases when meeting water; Sodium hydroxide belongs to the listed class 8 corrosive products. When transported by air, calcium oxide belongs to the eighth corrosion product listed in the list. The heating package belongs to the substances listed in the list that release flammable gas when it meets water.
According to the classification standard of the United Nations "Recommendations on the Transport of Dangerous Goods Model Regulations", the self-heating instant chafing dish products are dangerous goods in transportation, because of the danger of releasing flammable gas when encountering water.
Therefore, China’s civil aviation system has completely banned the carrying of self-heating products on the plane. The regulations on railway safety management issued by Guangxi also clearly stipulate that it is forbidden to use self-heating food on bullet trains.
Use reminder
Shanghai Consumer Protection Committee reminds consumers:
● Read the instructions of the product before use, and operate in strict accordance with the prompts, especially not in closed and narrow environments such as cars, avoiding naked flames, and minors can use it under the guidance of adults.
● When using, please pay attention to placing the product on the anti-scalding table, and avoid touching the outer pot to avoid scalding.
● After use, the instant chafing dish garbage should avoid massive accumulation or direct contact with water, and be classified according to the regulations of Shanghai Municipal Domestic Waste Management, and the used heating package should be classified and disposed according to harmful waste.
Self-heating food raw materials have the problem of nutrient loss.
Chen Rong, president of the Nutritionist Association of Heilongjiang Province and a national first-class nutritionist, said that the nutritional value of vegetable raw materials in self-heated food could not be compared with that of fresh vegetables.
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