【 Radiation from Induction Cookers 】 Does an induction cooker have radiation? Are induction cookers harmful

"Induction cooker radiation" can also be called "induction cooker leakage radiation". There is a certain amount of radiation in an induction cooker. This is because the magnetic field generated by a general induction cooker cannot be 100% absorbed by the cookware, and part of the magnetic field leaks out from around the cookware, thus forming electromagnetic radiation. Although the radiation frequency of an induction cooker is approximately one-sixtieth of that of a mobile phone signal, the power that truly determines the magnitude of the radiation is much greater than that of a mobile phone signal. This radiation power mainly depends on the leakage value of the electromagnetic waves from the induction cooker. The greater the leakage, the greater the harm to the user.

The sources of radiation from induction cookers

All household appliances emit radiation. However, the current 3C compulsory certification promoted by the state mainly focuses on product performance and safe use, such as whether there is leakage of electricity, and does not enforce electromagnetic compatibility items.

The working principle of an induction cooker is to convert a low-frequency alternating current power supply of 50HZ into a high-frequency alternating current power supply of 30KHZ-40KHZ, which is directly applied to the coil coil of the induction cooker to generate a high-power electromagnetic field. Then, the electromagnetic field is used to cause eddy currents in the pot body for heating. Generally, beneath the thermal insulation plate on the surface of an induction cooker, there is a copper coil, and the electrical energy conversion device generates an alternating magnetic field within the coil. The frequency is generally from 20kHz to 40kHz, belonging to the category of extremely low-frequency electromagnetic fields. When an alternating magnetic field passes through the ferromagnetic metal vessels on the furnace surface, eddy currents and hysteresis loss effects are generated, converting electrical energy into thermal energy.

When a common induction cooker is in operation, the electromagnetic radiation generated by the coil not only heats the pot on the surface of the cooker but also releases a portion of the electromagnetic radiation from the inside of the cooker and the pot, resulting in what people call leaked electromagnetic radiation. The intensity of the leaked radiation source is related to the power of the induction cooker and its quality. The more concentrated and upward the radiation position and direction of electromagnetic waves are, the more ideal it is. If they are directed towards the outer edge, significant leakage will occur.

Magnetic fields are all around us

The increasing demand for electricity, the rapid development of new technologies and changes in social patterns have created more and more sources of artificial electromagnetic fields, and the exposure to artificial electromagnetic fields in the environment is constantly increasing. From the generation and transmission of electricity, household appliances, industrial equipment to telecommunications and broadcasting, whether at home or at work, everyone is exposed to weak electric fields and weak magnetic fields that are mixed in complex ways.

The magnetic field is generated when current flows through it: the greater the current, the greater the magnetic field. In the environment around us, electromagnetic fields are everywhere, but our eyes cannot see them. During thunderstorms, the accumulation of local charges in the air can generate an electric field. The Earth's geomagnetic field can make a compass point in the north-south direction. Birds and fish use the geomagnetic field to determine direction.

In addition to natural sources, the electromagnetic spectrum also includes many electromagnetic fields generated by artificial sources: X-rays can be used to examine limbs that are accidentally fractured during exercise; The power of each power socket is closely related to extremely low-frequency electromagnetic fields. Radio waves with higher frequencies can be used to transmit information, whether through TV antennas, radio stations or mobile phone base stations.

The hazards of electromagnetic radiation

There is no dispute that electromagnetic fields exceeding a certain intensity can cause biological effects. Experiments on healthy volunteers have shown that short-term exposure to electromagnetic fields of normal intensity in the environment or at home does not cause any obvious harmful effects. Exposure to higher-intensity electromagnetic fields that may cause harm is strictly restricted by national and international safety guidelines. The current controversy mainly focuses on whether long-term low-intensity exposure will cause biological effects and affect humans.

The intensity of the radio frequency electromagnetic field that people usually come into contact with is much lower than that which can produce obvious heating effects. The heating effect of radio frequency electromagnetic waves is currently the main basis for formulating safety standards. Scientists are also studying the possibility of effects produced by long-term exposure below the critical value that can heat the human body. So far, the negative health effects of low-intensity and prolonged exposure to radiofrequency and power frequency electromagnetic fields have not been confirmed.

Electromagnetic radiation and cancer

In 2002, the International Agency for Research on Cancer classified extremely low-frequency electromagnetic radiation as a suspected carcinoid and, based on the combined analysis method in epidemiological studies, proved a consistent pattern: children's average exposure to residential power frequency magnetic fields exceeding 0.3-0.4μT would double the probability of developing leukemia. This conclusion was widely quoted by domestic media, causing panic among people about the safety of household appliances for a time.

However, in its review conclusion in 2007, the WHO provided a clear explanation for the health effects of electromagnetic radiation, stating that the conclusion of the International Agency for Research on Cancer, due to improper methods and the lack of effective biophysical mechanisms, could not demonstrate a causal relationship between electromagnetic radiation and childhood leukemia.

At the same time, the International Association for Non-Electrical Radiation Protection (ICNIRP) supported the review conclusion of the WHO, arguing that there is insufficient evidence to prove the pathogenicity of low-frequency electromagnetic radiation, and chronic exposure to low-intensity low-frequency electromagnetic radiation will not cause disease. However, it also indicates that low-frequency electromagnetic radiation with high electric field intensity can cause physical discomfort to those exposed (not pathogenicity).

ICNIRP indicates that low-frequency electromagnetic field exposure has some confirmed acute effects on the nervous system: direct stimulation of nerve and muscle tissues as well as triggering retinal photohallucinations. There is also indirect scientific evidence suggesting that brain functions such as visual processes and motor coordination may be briefly affected by induced electric fields. All these effects have thresholds. Below these thresholds, they will not occur. As long as they meet the basic limits of the induced electric field within the body, these effects can be avoided.

Are induction cookers harmful

The alternating magnetic field generated by the electrical energy conversion device of an induction cooker generally has a frequency ranging from 20kHz to 40kHz, which falls within the category of extremely low-frequency electromagnetic fields. Therefore, the view that "electromagnetic pollution can induce cardiovascular diseases and even cause cancer" does not apply to low-frequency household appliances such as induction cookers.

At present, there is no scientific evidence to prove that low-frequency electromagnetic fields can cause diseases in humans. Therefore, the claim that "induction cooker radiation may cause cancer", as well as the conclusions drawn from it that "pregnant women and children should avoid using induction cookers as much as possible" and "induction cookers should not be used for too long", all have no factual basis. As long as it is a regular manufacturer and has passed the electromagnetic strength test, there is no need to worry about the issue of electromagnetic radiation during use.

So we need to eliminate radiation risks at the very beginning of the purchase. When purchasing an induction cooker, it is essential to choose a well-known and reputable brand. Generally speaking, the more reputable the induction cooker is, the stricter its production standards will be, and relatively, the less electromagnetic radiation it will emit. When choosing a pot, iron and steel products should be the main options. This is because such ferromagnetic materials can match the heating load (pot body and stove) with the induced eddy current during the heating process, resulting in a high energy conversion rate and relatively less magnetic field leakage.

In addition, when purchasing an induction cooker, ask the seller for an electromagnetic induction intensity test report. Most induction cookers come with this. Use this report to compare and choose an induction cooker with relatively low electromagnetic radiation.