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It is not currently known whether magnetic magnetic fields originating from induction hobs represent a health risk. These magnetic fields can be reduced by correct use of the induction hob. The following tips will help you to get the best results:
|1 Induction coil||5 Indication of operation|
|2 Temperature sensor||6 Base of pan made of ferromagnetic material|
|3 Thermal insulation||7 Alternating electromagnetic field|
|4 Glass ceramic plate|
The stray fields measured with inappropriate pans were up to 3.5 times larger than those measured with appropriate pans (Figure 2).
Appropriate pan, centred vs. inappropriate pan, off-centre
Figure 4 compares the stray fields from an appropriate, centred pan and an unsuitable, off-centre pan (worst case). The stray fields in the worst case are up to 9.5 times larger than the stray field generated by the use according to the standard.
Stray fields are larger the closer to the cooking field they are measured. At a distance of 30 cm, all models comply with the reference value of 6.25 microtesla (µT) recommended by the ICNIRP. In most cases the stray field measured 1 cm in front of the edge of the cooking zone exceeds this reference value. With an off-centre placing the stray field reached the reference value at a distance of < 1 cm to 12 cm with appropriate pans and < 1 cm to 20 cm with inappropriate pans. All measurements were carried out with the hob at the highest setting. A distance of 1 cm is unlikely to occur in normal daily use and represents a worst-case scenario. None of the measurements exceeded the ICNIRP reference value at a distance of at least 5 - 10 cm, the distance most likely to occur in practice, when the pans were used correctly (suitable cookware, centred over the cooking zone).
The magnetic field originating from induction hobs leads to electrical currents running through the body of a person standing in front of the hob. In order to avoid acute reactions such as nerve or muscle stimuli, these currents may not exceed the respective reference values set by the ICNIRP for the general public.[TMX1]
Body currents cannot be measured directly; they have to be calculated with computer simulations using virtual model persons. On behalf of the FOPH, the IT'IS research foundation in Zurich undertook such simulations for models standing directly by the worktop in front of the three tested induction hobs and who are cooking with properly positioned pans suitable for induction hobs. In addition to the magnetic currents, the simulations also took into account gender, age, build, anatomy, tissue characteristics and posture of the following virtual persons:
The body currents were simulated for the entire body as well as specifically for the central nervous system (brain and spinal cord) of persons standing directly by the edge of the worktop. In this position, users tend to be a few centimetres away from the cooking field that is built into or on top of the worktop. The simulation assumed that the models were cooking with pans that were suitable for induction hobs and centred on the cooking zone, covering it up completely. Figures 5 and 6 depict the maximum exposures vis-à-vis the reference value.
The results show that the body currents emanating from the two built-in units fall below or right on the reference value for most models, with the exception of the woman who is nine months pregnant and the six-year-old child, both of whom show body currents above the reference value. The body currents generated by the professional high-performance mobile unit are mostly above the reference value (figure 5). The central nervous system currents are below the reference value for all models (figure 6).
Some studies have looked at the way induction hobs affect implanted electronic devices [7-10]. The possibility cannot be excluded that stray magnetic fields generated by induction hobs may affect implanted electronic devices at short range; this has been demonstrated for unipolar cardiac pacemakers . Also the effect of leakage current on unipolar cardiac pacemakers has to be borne in mind. People with unipolar pacemakers are advised not to touch pans for extended periods and not to use metal spoons for cooking . It is vital for people with implanted electronic devices to read the safety advice provided by the manufacturer and talk to their doctor before using an induction hob. The likelihood of the implanted device being affected adversely is very low if the induction hob is used correctly.
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