Is induction cooking safe? Because induction stoves are electrical, they have all the hazards of every other electrical appliance in your home. That is, they emit electromagnetic fields (EMFs). But how hazardous are these EMFs, and how dangerous is an induction stove? Depending on who you ask, they might be very hazardous to human health, linked to all sorts of ailments from headaches and nausea to malignant tumors. Or, they might be completely harmless, just another aspect of the normal backdrop of modern life.
Here at The Rational Kitchen, we love induction cooking, so yeah, we’re biased. But above all, we are interested in what the science has to say. And the truth is that the science supports our belief that induction cooking is safe.
We could end the article there, but that wouldn’t be very helpful, would it? It would simply be our word against the anti-induction people who have a huge Internet presence (frequently under the guise of scientific organizations, so watch out!) On the other hand, to really, fully, completely answer this question, we would have to have a fairly lengthy conversation about a lot of complicated things like the Electromagnetic Spectrum and the difference between ionizing and non-ionizing radiation.
We’re going to try to have that conversation, as simply as we can yet still explain enough for you to make an informed decision. Because to really understand the issues involved with induction cooking, you have to have some background information. But you don’t need to become a physicist.
Regardless of what you might read on the Internet, the actual science overwhelmingly supports the fact that induction cooking is safe.
How Induction Cooking Works
Induction cooktops use electricity to create energy, just like every other appliance in your home. But unlike most other home appliances, induction cooktops have a fairly powerful magnetic field. This is what makes people wary about them.
Here's how it works.
Induction burners are essentially electromagnets--that is, they're copper coils that, when electrical current is passed through them, become magnetic. When you place a ferrous (i.e., magnetic) pan on the burner, the pan becomes sort of an extension of the electromagnet. Magnetic steel has a very high heat loss factor at the frequency of the current being passed through it--in the case of induction, around 24 kHz (according to Wikipedia).
This "heat loss" is how the pan gets hot, and the reason why only ferrous metals will work with induction burners. This loss also happens very, very quickly, which is why induction cooking is so fast and so efficient.
(Update: There is now an induction cooker that works with non-ferrous cookware, but the technology still leaves something to be desired.)
Here's a short video that shows how the electromagnetism of induction works (courtesy Ramanuj Nanhoriya):
Because the pan itself becomes magnetized, a small amount of current (also called electromagnetic frequency, EMF, electromagnetic radiation, or simply radiation) passes from the cookware into your body when you touch the pan. This is one of the reasons some people are wary of induction technology, more so than of standard electric ranges (which emit only the standard radiation of all other household appliances).
If you don't understand what that means, it does sound scary. But it's really not--read on to find out why.
Why Is there So Much Controversy About EMFs?
In the 1980s, a study was published that found a correlation between higher rates of cancer (specifically, leukemia in children) and proximity to power lines. EMFs were classified as a 2b carcinogen by the International Agency for Research on Cancer (IARC). A 2b classification means possibly carcinogenic to humans--but no conclusive evidence has yet been found. (More on this in a minute.)
Since then, thousands of studies have been done by scientists all over the world, in both the public and private sector, to corroborate these findings. To date, nobody has been able to substantiate the findings of the initial study, and no causal relationship has been definitively drawn between power lines and higher rates of cancer, in any form, for people who live near them.
Other sources of EMFs have also been extensively tested, such as mobile phones, and have found no conclusive evidence that the radiation emitted by electrical devices has a negative or lasting effect.
But the Pandora’s box was opened. Many people distrust these findings and insist that all EMFs emit dangerous levels of radiation, that the government is lying to us, or just that it is “better to be safe than sorry” because even if there isn’t conclusive evidence of danger, there’s enough controversy to make it a probable concern. Right?
Well, not really, no.
All the hype and controversy surrounding electromagnetic fields is rooted, like most things we fear, in ignorance. The truth is that EMFs can be dangerous. And it's important to understand when and under what circumstances this is the case. But the truth is also that EMFs that come in contact with people in normal, daily routines generally are not.
What are Electromagnetic Fields (EMFs)?
According to the World Health Organization:
“Electric fields are created by differences in voltage. They exist wherever there is a positive or negative electrical charge present. The higher the voltage, the stronger will be the resultant field. Magnetic fields are created when electric current flows: the greater the current, the stronger the magnetic field. An electric field will exist even when there is no current flowing. A magnetic field only occurs when current flows.”
Thus, electric fields and magnetic fields exist together, and they exist anywhere there is an electrical charge. This is why they are lumped into one category and called electromagnetic fields. The emissions from these fields are called “electromagnetic radiation” or simply “radiation.” (Yes, that radiation--sort of. More on that in a minute.)
EMFs come from many sources. They exist in abundance in nature, such as in the atmosphere (thunderstorms are the result of a buildup of electrical charge) and the earth itself (its magnetic poles can be read by a compass and are used by birds and animals to navigate). The sun is a huge source of electromagnetic radiation, including both visible and ultraviolet light. In fact, the sun is an excellent example that shows the mixed bag that EMFs are: the ultraviolet rays from the sun are harmful to human flesh and are estimated to cause about one million cases of skin cancer per year. However, life on earth would not exist were it not for the visible light from the sun--photosynthesis, for example, would not be possible.
So you can begin to see that EMFs, even naturally occurring EMFs, can not easily be labelled “good” or “bad.” It's more complicated than that.
Nobody really concerns themselves too much about naturally-occurring EMFs (even though the sun is by far the most dangerous source of radiation that most people are exposed to on a routine basis). It’s the man-made EMFs people worry about.
Man-made EMFs surround us. Unless we go “off the grid” completely, we are bombarded by man-made EMFs pretty much constantly. The laptop I’m typing on right now is a source, as is the ceiling fan above me, the lamp sitting next to me (even though it’s not on), all the wiring in my house, the WiFi I rely on and my innocent-looking cell phone at my elbow (which uses microwave technology, which can, in some situations, be highly damaging to human tissue). And in the kitchen, all of your appliances are sources, including--yes--your induction cooktop.
All electrical appliances generate electromagnetic fields--AKA radiation! As do all the cell towers, radio towers, and power lines you see and live with every day. And when you go to the doctor, you may be X-rayed or given an MRI--these, too, generate radiation. In the case of X-rays, extremely dangerous radiation.
The Electromagnetic Spectrum
So why aren’t I more worried about all this radiation I’m exposed to? This is where it starts to get a wee bit complicated. To understand this, it might be helpful to talk a little bit about the Electromagnetic Spectrum, which you or may not remember from your middle school science classes. According to Wikipedia, “The electromagnetic spectrum is the collective term for all known frequencies and their linked wavelengths.”
The ES includes radio waves, ultraviolet light, visible light, infrared waves, microwaves, X-rays, and gamma rays, as well as some other, lesser known waves.
Why is this important to know? Because it allows you to see that all of these EMFs exist along a spectrum. If you understand this, even in an undetailed way, you can see that EMFs are just a part of everyday life, from listening to the radio to using your cell phone to laying on the beach. Our vision and our hearing are both the result of human interaction with different electromagnetic waves.
More importantly, you can begin to sort out the non-harmful EMFs from the harmful ones. And if you can do this, you can make rational choices about which EMFs you'll want to avoid and which ones make your life easier.
To do this, though, you need to dig just a little deeper to learn about frequency and wavelength.
Frequency and Wavelength
Frequency, typically measured in Hertz, is the number of waves in a given distance. Wavelength, typically measured in nanometers, is simply the distance between the waves (as measured from crest to crest):
All EMFs have specific frequencies and wavelengths which identify them. For example, visible light exists at wavelengths from 400-700 nanometers.
A good analogy (from the WHO study on EMFs quoted above) to help understand frequency and wavelength is if you tied one end of a rope to a door and swung the other end. If you swing the rope slowly, it results in long waves (low wavelength) at a low frequency (that is, a large distance from crest to crest). If you swung the rope rapidly, it would result in many small waves (higher wavelength) that were closer together (higher frequency).
Just as the rope that is swung harder has more energy in it, so do wavelengths with higher frequency. In fact, this is the primary way to determine how dangerous the radiation of an EMF is: waves at the low end of the ES, such as radio waves, are very long--they can be hundreds of feet long--so they have a very low frequency. But at the other end of the spectrum we find short waves with a very high frequency. These are the ultraviolet, X-rays and gamma rays. They’re what’s known as ionizing radiation, which is the type that can penetrate the human body and destroy cell tissue. Ionizing radiation waves are dangerous at even low levels of exposure.
Ionizing Versus Non-Ionizing Radiation (The Crux of the Matter)
High- and low-frequency radiation are also classified as “ionizing” and “non-ionizing” radiation. “Ionization” refers to the ability of radiation to break chemical bonds, including in living tissue. Too much breakage can result in abnormal cell growth (cancer). This is why these high-frequency waves are so dangerous (e.g., why we wear sunscreen and should avoid getting too many X-rays and airport scans.)
Ionizing radiation is also cumulative: that is, the effects on the body build up over time, so even small doses (like X-rays) if repeated enough can have serious effects.
Non-ionizing radiation comprises pretty much everything below ultraviolet on the ES. Because these waves are long and slow-moving (that is, they have a low frequency), they don’t have a lot of energy. When they come in contact with solid objects, including the human body, they simply bounce harmlessly away. It’s like if a 3-year old child was throwing ping pong balls at you: no matter how hard he tried, he wouldn’t be able to hurt you.
Power Does Matter
There’s one more consideration about non-ionizing EMFs, and that is the amount of power a given EMF has. If a source of non-ionizing radiation is strong enough, it can make a person sick: numbness, tingling, nausea, and headaches are the most common symptoms. And if it is extremely strong, it can cause serious burns and even electrocution if there is direct contact with the body.
Most people do not come into contact with sources of non-ionizing radiation that are powerful enough to be harmful. And those who do (such as technicians who work on radio antennas) have well-established guidelines for exposure limits.
But the most important thing to remember about non-ionizing radiation is this: Even though non-ionizing radiation can be harmful at high levels, it does not work the same way as ionizing radiation. Non-ionizing radiation can NOT change cell structure, and there is no evidence of cumulative effects. This means that if you’re near equipment that’s generating a lot of power and you’re starting to feel dizzy or get a headache, all you have to do is get away from it. The symptoms will stop, and there will be no permanent damage to--or cumultive effects on--your body.
Extremely low frequency (ELF) magnetic fields are classified by the IARC as a 2b carcinogen (that is, possibly carcinogenic). But to date, no studies have actually proven causality.
Why are they classified this way, then? We’ll talk more about that in a minute.
Even though non-ionizing radiation can be harmful at high levels, it does not work the same way as ionizing radiation. Non-ionizing radiation--that is, everything below ultraviolet--can not change cell structure, and there is no evidence of cumulative effects. The radiation generated by induction cooktops, as well as all other household appliances, is non-ionizing.
Exposure Levels and Safe Limits
Safe exposure guidelines exist for all levels of radiation. These include not only occupational exposure limits but those for all appliances and devices designed for home use. These safe exposure guidelines are complicated, and not easily explained. Here is a link to a site that discusses EMF exposure in the US--but be forewarned that it is not easy information to make sense of.
The upshot is that it is extremely rare for any home appliances to operate outside of these guidelines.
Home Levels of EMFs
Here’s a brief explanation of why you don’t have to worry about EMFs in the home. Most modern houses have 200 amperes of power running into them. This is simply not enough power to create EMFs that can damage the human body. And even if it were enough power to be harmful, turning off the offending appliance--or simply stepping a few feet away from it--solves the problem. (Why does this solve the problem? Because all household appliances emit non-ionizing radiation.)
No home appliances emit dangerous levels of radiation, non-ionizing or otherwise. And with the consensus among scientists being that there is no cumulative effect of non-ionizing radiation, there is little evidence that you are in any danger from any of your home appliances, including your induction stove. And this is true even if you’ve got every appliance in your home running at full power at the same time, all bombarding your body with non-ionizing radiation.
The only possible exception is your microwave--but even with this appliance (which by the way does not use ionizing radiation to cook food), the microwave has to be malfunctioning to leak any radiation, and you have to be closer than a couple of inches for it to do any damage. At distances of even half a foot, the emissions drop off to an almost immeasurably small amount.
But What About All the Cancer?
It’s true that extremely low frequency magnetic fields and radiofrequency EMFs have been classified by the International Agency for Research on Cancer (IARC) as class 2b carcinogens. This sounds compelling--but what exactly is a class 2B carcinogen?
According to Wikipedia, the IARC defines it as “The [2B] agent (mixture) is possibly carcinogenic to humans. The exposure circumstance entails exposures that are possibly carcinogenic to humans. This category is used for agents, mixtures and exposure circumstances for which there is limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals.” (emphasis added)
In other words, there is no compelling evidence of a causal relationship between a Class 2b substance and cancer. It hasn’t been entirely ruled out, however, none of the studies have shown actual evidence that a link exists.
Not a single study has proven a link between a Class 2b substance and cancer.
Because EMFs have been of interest since the 1979 study that proposed a link between power lines and childhood leukemia, there have been tens of thousands of studies done, most of which have refuted the findings of the power line/leukemia relationship (and none that have supported it). Organizations throughout the world, both public and private, have reviewed findings and conducted new studies on a regular basis. And no conclusive evidence has yet been found that links non-ionizing radiation and cancer.
Just to give some perspective, here are some other substances on the class 2b list: coffee, pickled vegetables, and aloe vera gel. Coffee has been on the list since the early 1970s and has repeatedly been proven to not be a carcinogen (in fact, it seems to actually reduce the rate of some cancers). Yet there it remains--once again, because you can't prove a negative.
As for the rising rates of cancer in the modern world: according to scienceblog.cancerresearchuk.org, the main factor for increasing rates of cancer is age. People are living longer, and they estimate this accounts for about two-thirds of the increase.
But Shouldn’t I Be Skeptical, Anyway? (Better Safe Than Sorry?)
This is the attitude of many people. Millions, in fact. And they are all over the Internet and elsewhere, telling you that you should have this same attitude, “just in case.” But if you understand the facts, then you don’t have to play “what if” and “just in case.” You can make informed decisions for yourself and your family.
So yes, be skeptical--always! But be skeptical about the right stuff. Remember that, when you find information on the Internet, you shouldn't believe any of it without verification. (And yes, that includes our articles on Rational Kitchen, too.) Look at their sources and the language they use. Are they linking to established studies and scientific sites? If so, are they quoting these studies honestly or out of context? Is the language emotionally charged, with terms like “toxic” and “dirty” and “poison”? Or does it strive to be objective and intellectually honest?
There are a lot of people out there spreading misinformation. Even if they mean well, their opinions may not be grounded in the actual science on the subject. When it comes to understanding technical matters you should look to the science because that’s where you will find the truth.
Yes, it can be a pain to verify information. But the internet has made it easier than ever before. You have an entire world of information at your fingertips. Don't just believe the first source you find (including us). Check and check again.
So What’s the Upshot? Is Induction Cooking Safe or Not?
To date, very few studies have been done on the effects of induction cooking devices on humans. But because we have a good understanding of EMFs, electricity, radiation, and the power levels generated in the average home--all the elements involved in induction cooking--we can say with virtual certainty that an induction stove is as safe as any other appliance you have in your home.
That is to say, induction cooking is safe.
In fact, even the study most often quoted by induction-phobes says there is no evidence that EMFs are dangerous.
The study advises that people, especially pregnant women and small children, should avoid close contact (less than 30 cm/11.8 inches) with induction burners because of the stray radiation given off by them under certain conditions (such as when cookware is not properly centered on the hob).
However, if you read the entire study, it explains that even as close as 1 cm, the radiation does not exceed safe limits and, more importantly, that “According to the World Health Organization (WHO), there is no compelling evidence of medium-frequency magnetic fields having long-term effects on health.”
If you understand how electricity works, you shouldn’t find this surprising. (Remember the little kid with the ping pong balls we talked about earlier?)
Furthermore, since the radiation emitted by an induction burner is non-ionizing, if you did happen to feel tingling or numbing, simply move away from the burner--problem solved! But unless you hold your hand directly over the burner for a very long time--hours, most likely--this is extremely unlikely to happen.
Pot Size/Placement Issues
If your pot doesn’t fully cover the induction burner or if it not quite centered, the amount of stray radiation given off by an operating burner increases significantly. However, even the worst case scenarios--standing directly next to a small, improperly placed pot--does not result in levels of radiation that exceed safety guidelines, even for pregnant women and small children.
How About Pacemakers?
Because certain pacemakers are affected by EMFs, you should consult a doctor before buying an induction stove if this is a concern for you. The radiation generated by an induction stove is unlikely to be strong enough to affect pacemaker operation unless it (the pacemaker) is within an inch or two of the burner. But this is the one case with induction where you are “better safe than sorry.”
The fact that some induction hobs can affect pacemaker operation in no way means that they are "dangerous" or "unhealthy." It just means that they operate on a frequency that interferes with the frequency of the pacemaker.
What the Experts Have to Say
The following statements are from organizations in the past 10 years. Note the huge variety of organizations across the globe which have come to similar (if not identical) conclusions.
The National Cancer Institute (part of the NIH): No mechanism by which ELF-EMFs or radiofrequency radiation could cause cancer has been identified.
The Institution of Engineering and Technology: ...has concluded that the balance of scientific evidence to date still does not indicate that harmful effects occur in humans due to low-level exposure to EMFs. This conclusion remains the same as that reached in its previous position statements, the last being in May 2008, and has not been substantially altered by the peer-reviewed literature published in the past two years.
Latin American Experts Committee on High Frequency Electromagnetic Fields and Human Health: ...the general conclusion, after more than 20 years of in vivo studies, is that no consistent or important effects of RF could be demonstrated in intact animals below international safety standards."
The European Commission: There is no conclusive scientific evidence of any adverse health effects below the protection limits of exposure to electromagnetic fields proposed by the International Commission on Non-Ionising Radiation Protection (ICNIRP), implemented in Europe by the Council Recommendation 1999/519/EC. The advantage of applying the ICNIRP guidelines is their solid scientific basis of established biological effects.
Health Canada: Based on scientific evidence, Health Canada has determined that exposure to low-level RF energy, such as that from Wi-Fi equipment, is not dangerous to the public, and The IARC classification of RF energy reflects the fact that some limited evidence exists that RF energy might be a risk factor for cancer. However, the vast majority of scientific research to date does not support a link between RF energy exposure and human cancers.
We could list dozens more quotes, and if you want to see them, check out this ICES link (also listed in the Sources section below). All of these organizations are saying the same thing: there is no evidence of human harm from EMFs in the amount we are normally exposed to on a routine basis.
EMFs remain classified as a 2b carcinogen--possibly carcinogenic--not because they’re dangerous, but because it is extremely difficult to prove a negative. In other words, more and more scientific evidence will continue to accumulate, assuring us that no relationship between EMFs and human peril exists. But that doesn’t mean we can say conclusively there is no danger. This is how science operates. It can prove a positive--the relationship between smoking and lung cancer, for example--but it can’t conclusively prove a non-relationship; they can only state that a relationship hasn't been found yet.
So those EMFs will continue to stay on the IARC 2b classification list, right along with coffee and aloe vera gel.
Smart people are careful. They take precautions and avoid dangerous situations as much as possible. Sometimes these are easy decisions, such as not smoking and not walking alone in a bad neighborhood after dark. But sometimes, the decisions aren’t so easy. The right decision isn't so obvious. When this is the case, it’s important to educate ourselves and form objective opinions based on science-backed evidence.
This is what we did for induction cooking. And even though we are biased (we love induction cooking!), we reviewed hundreds of websites to educate ourselves about the issues involved: primarily, the electromagnetic fields produced by induction cooktops. In the end we could find no conclusive evidence that induction stoves are any more dangerous than any other home technology, in the kitchen or otherwise.
If you have a pacemaker, consult with your doctor before purchasing an induction stove. Otherwise, don’t worry about induction cooking any more than you would about reading your email or talking on your cell phone. There is simply no evidence that any danger exists.
Finally, if we've convinced you to take another look at induction cooking, check out some other articles:
Or check out the Induction category at the top of the page for even more informative articles and product reviews.
Thanks for reading!
A PDF of the study (most often quoted by induction naysayers):