Induction cooktops are usually promoted as a safe and clean cooking device for the kitchen. They are sold on the basis of two huge advantages- energy saving and safety.
Built-in Safety Features in Induction Cooktops
Most of the induction cooktops have built-in safety functions to reduce potential fire hazard. The safety functions embedded are as follows:
- Automatic shut down if no cookware on top
- No power output once cookware is removed
- Automatic shut down if running continuously for two hours without any changes in temperature/power
- Safety cut off in case of overheating
- It does not have naked flame so heating up of the kitchen is reduced.
- The rest of the cooktop area remains cool so there is no risk of burns or ignition of spilled oils and fats.
- No emission of harmful gases.
- Embedded fan to prevent residual heat accumulation inside the cooktop
The induction cooktop generates the energy to heat up the cookware, and in turn, the cookware heats up the content inside the cookware. The content being oil used as a fuel to cook food.
Any improper and careless use of any of these three elements can lead to induction cooktop fire.
Induction Cooktop Elements that can cause a fire
Let us look into each element that may cause a fire.
The major component in the induction cooktop is glass-ceramic plate and heating element coil.
What basically happens is that when current is passed to the copper coil, it generates a high-frequency magnetic field. This field penetrates the ferromagnetic cookware.
The material is usually iron or stainless steel.
An eddy current is generated in the cookware. The heat in the cookware is then transferred to the cookware contents. More than 50% of the cooktops provide timer and temperature control as a safety measure.
Cookware is yet another important element in induction cooker fire hazard. Not all materials are suitable for induction cooking. They must contain ferromagnetic material such as iron or stainless steel.
One method to check is to place a magnet at the bottom of the cookware. If it sticks then it is induction compatible.
While considering the performance of the cookware, thermal properties such as thermal heat efficiency are taken into account. Stainless steel has the lowest heat transfer efficiency.
Manufacturers design different patterns of cookware bottom. The purpose of these designs is even heat transfer and distribution. The design on the bottom and the diameter of the cookware are important elements that affect the design of safety devices of the cooktop.
When uneven base cookware and undersize cookware is used, the response time of the safety sensors increases.
When we consider cooking oil properties in relation to induction cooker fire hazard, there are few things that are taken into account.
They are smoke point temperature, flash point temperature, and fire point temperature.
Smoke point temperature is the temperature of heated up oil that begins to give off smoke. Flashpoint temperature is the temperature of the heated oil that gives flashes of burning when exposed to a flame. The fire point temperature is the temperature at which heated oil sustains burning after ignited by a flame.
Different oils have a different smoke point, flash point, and fire point temperature.
How fire can be caused by induction cooktop
The main part of the induction cooktop consists of a control panel, ceramic plate, and a power cord.
The ceramic plate can withstand certain high degree temperatures. About 600-degree centigrade approximately as quoted online. However, the power cord is not a fire-resistant cable. It can be ignited and can be easily damaged by fire.
If the oil is heated up to the extent of smoke being filled up in the kitchen and no effort is made to correct the situation, in approx 12 mins an auto-ignition fire can be started by the same oil according to an experimental study of induction cooktop fire by Hong Kong polytechnic university.
Once the fire is auto-ignited in the cookware, it was noticed that the induction cooktop did not shut off on its own. The shut down had to be done manually.
One of the reasons why the safety feature did not trigger in the induction could have been because of improper cookware. Heat transfer occurs from the base of the pan to the cooktop. If the heat transfer from the cookware base and the ceramic plate is poor, heat transfer is reduced.
During their study, they also found that the fire can reach a level of 1.2 meters.
This implicated that the presence of any inflammable material within 1 meter above the induction unit can cause the material to flame up easily
When the quantity of oil was increased, the fire started earlier. The difference found was 32 seconds.
Thanks to the study done by the University of Hong Kong, induction cooking fire hazard is very real. More details can be found here. The safety devices failed and were unable to get triggered.
Anything which needs to be operated can be risky and so is this cooktop. overheating the oil can lead to fire hazard. The fire hazard is also subjected to the quantity of fuel oil, fuel oil type, selection of cookware and also the selection of induction cooktop.
As a precaution, inflammable materials should be kept at least 1 -2 meters away from the induction.
Never keep anything magnetic and inflammable near the cooktop as the induction works on electromagnetic radiation.
Always remove the cookware from the cooktop once the cooking is done unless you want to keep it warm temporarily by using the residual heat.
Any gadget can malfunction and is never 100 percent safe. Take care of all the precautions beforehand. Remember improper use of induction cooker can certainly lead to it becoming a kitchen fire hazard.
Have a safe Induction cooking!
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