February 21

How Much Radiation Does a Microwave Oven Emit? | We Addressed Your Concerns!


Author: Colin Ma
Kitchengearoid.com and its partners may earn a commission if you purchase a product through one of our links.

Microwave ovens are kitchen appliances that have proven to be very versatile over the years.

Since their accidental invention in the 1940s, microwave ovens have grown in popularity and have found their place in numerous countertops in homes and business premises alike.

While the amount of radiation emitted from a Microwave varies from model to model, FDA standard limits the lifetime emitted microwave radiation to 5 milliwatts, which is far below the harmful level. (Read FDA Article)

A lot of skepticism has followed the safety of the use of these devices.

Having noted this, let’s delve deeper into microwave ovens and find out how much radiation does a microwave oven emit.

Many claims have arisen over the years stating that microwave ovens are more harmful than they are useful and that their use in homes should be halted.

While there is some truth to some of these claims, indeed, microwave ovens do produce some radiation with which they heat food, however a lot of the speculations about their safety remain in the realm of myth.

World Health Organization (WHO) has already dispelled the myths surrounding the safety concerns of a microwave IF it is used according to the manufactures instructions and IF necessary precautions are taken such as not using a damaged microwave appliance.

Also Read: How Does a Microwave Oven Work?

What is Radiation?

In simplest terms, when energy is transferred through space from one object to another without any sort of contact, it is called radiation.

Now there are several types of radiations.

Acoustic radiation relates to sound such as that emitting from speakers to your eardrums, ultrasound that is used for medicinal and other purposes etc. This type of radiation, obviously, isn’t harmful.

The second type of radiation is electromagnetic radiation.

What is Electromagnetic Radiation?

How Much Radiation Does a Microwave Oven Emit
The image shows the frequency and wavelenth of microwaves in the larger electromagnetic spectrum. Source: Wisegeek

In science, there is a spectrum that depicts the different kinds of electromagnetic waves existing around us.

These are categorized by wavelength and the spectrum varies from those with shorter wavelengths to those with long ones.

Among the long-wavelength electromagnetic (EM) waves are radio waves and microwaves.

Microwaves, like all other EM waves, are composed of both an electrical component and a magnetic component, hence the name.

Electromagnetic radiation include infrared, radio waves, microwaves, X-Rays etc.

Now the electromagnetic radiation with longer wavelengths like radio waves, and microwaves are considered safe according to International Commission on Non-Ionizing Radiation Protection.

These SAFE Electromagnetic Radiations including Microwaves are called non-ionizing radiation.

Ionizing vs Non-Ionizing Radiation

ionizing vs non ionizing radiation
Source: Mirion.com

Microwaves belong to the non-ionizing radiation. Meaning they do not carry enough energy to break the chemical bonds. In other words, it does not alter your chemistry when exposed.

Ionizing Radiation, on the other hand, like X-Rays, Gamma Rays, and particle radiation carry enough energy to alter your biological structure as they can break bonds if exposed to enough. Hence, these are dangerous if exposed to large amounts.

Also Read: Where Can I Recycle My Microwave?

How a Microwave Produces Radiation

The American Cancer Society describes radiation as the emission of energy from a source. In this regard, a microwave oven can also be considered a radiation source.

When a microwave oven is in operation, a transformer receives the power supplied to the device and steps it up to a higher voltage that can be used to generate microwaves.

Magentron Assembly
Magentron Assembly

The main process occurs within the device’s magnetron assembly. This is the device that generates the waves we commonly use to cook our food.

Microwave energy gets emitted through a complex process that involves the heating of a central cathode in the magnetron.

This results in a release of electrons that try to jump to an anode. A magnetic field forces the electrons to move in a curved path within the magnetron assembly. The outer cover has cavities and as the electrons interact with these cavities, microwave energy is produced.

Once this radiation is produced, it will need to be guided to the food inside the microwave to either heat it or cook it. A waveguide is used for this purpose.

Microwave Radiation Characteristics

Microwaves travel from their source in the form of a wave. They have low energy and can therefore be easily reflected by a sheet of metal. This is why microwave ovens are often metallic.

Microwaves interact with some kinds of matter in particular ways. The most useful for a microwave oven being that these waves can be absorbed by certain molecules (like those in food) and causes those to vibrate thereby generating the heat to cook the food.

Microwaves can also be refracted and when interacting with certain materials, they can lose all or some of their energy, a process known as attenuation.

So How Much Radiation Does a Microwave Emit?

As mentioned earlier, microwave ovens produce non-ionizing radiation. As opposed to ionizing radiation, non-ionizing radiation does not possess enough energy to strip electrons from atoms.

Ionizing radiation does and this is the kind of radiation that leads to problems such as DNA damage.

When it comes to numbers, the amount of radiation that a microwave oven will depend on the model and the operating mode it is.

Nevertheless, microwave ovens come with a lot of shielding from the harmful microwaves to protect users for burns and other severe injuries.

Acceptable Radiation Levels

It is important to set safety standards that ensure manufacturers stick to the agreed-upon guidelines for the maximum amount of radiation microwaves are supposed to expose people to.

To oversee this issue, the FDA (Food and Drug Administration) has come up with directives on the maximum amounts of radiation a person can be safely exposed to.

The FDA states that the maximum amount of radiation that can emitted from a microwave oven over its lifetime should not exceed 5 Milliwatts.

This number takes into account the distribution area of the radiation as well as the distance from the source of the radiation, in this case, the device itself.

So, at a distance of two inches from the source and within an area of one square centimeter, this value should not be exceeded.

This value is way below the absolute value that can cause any serious harm to a person but it is set so to ensure the risks to human health are minimized.

To put your mind more at ease, microwave energy attenuates drastically, meaning that at just 20 inches from the source of the radiation, the average power can be just a mere one percent of the radiation detected at 2 inches from the source.

Levels below the maximum provided by the FDA are ideal, however, exposure to levels above the given minimum can have dire consequences to the person exposed. They may not lead to cancer, but you might walk away with serious burns.

Of course, to further answer your questions and put your mind to ease you must get in touch with your manufacturer, FDA or other government health department with experts in this field.

Effects of Microwave Radiation

Believe it or not, you’re constantly exposed to microwave radiation. Some of it comes from space and some can be from terrestrial events like lightning strikes.

In low quantities, the effects of microwaves can go unnoticed; however, in high quantities, this can burn tissue.

Microwave Usage Safety

Radiation from microwaves is harmless, as long as it stays inside the microwave.

You typically do not want this energy to escape the confines of the device and one way is to ensure that you use a microwave with a fully functional door.

The door not only lets you put in and see your food, but it also has a metal mesh that blocks harmful radiation from going through the glass.

Do not disassemble the device if you’re not a trained professional.

Doing so could put you at risk of electrical shocks as well as can damage the insulation protecting you from the microwaves.

Lastly, microwaves come with a double switch system that makes sure you can’t switch it on while the door is open.

Ensure this is the case before using your unit to prevent any accidents.

Also Read: What is a Built-in Microwave?


In this article we looked at a common concern: “how much radiation does a microwave oven emit?”

Having a microwave oven comes with its bag of concerns that have been predicated in most cases by a lack of clear understanding about the kinds of radiation they produce, how they are produced, the amount delivered and their effects.

As seen, microwave radiation is all around us and has various uses from communication to cooking.

It is apparent that microwave ovens do produce high amounts of this radiation but it is well confined within the machine during operation.

Since they produce radiation, users should be careful when using microwaves to avoid personal injury or damage to the machine.


1. Do microwaves give off radiation?

Technically, microwaves do emit radiation, but it is not the DNA-damaging radiation we used to hear. Microwaves, along with radio waves from radio and cell phone towers, are all examples of non-ionizing radiation. This radiation is not harmful to us humans.

2. What happens if your microwave leaks radiation?

The only risk associated with a leaking microwave is the excessive heat generated. This is particularly harmful to the eye (where it can cause cataracts) and testes (where it can cause temporary sterility). Microwave radiation at extremely high levels can burn the skin.

3. Can humans see microwave radiation?

No, our eyes do not have the capability to see microwave radiation.
The human retina is only capable of detecting incident light with wavelengths between 400 and 720 nanometers, which means that we cannot see microwave or ultraviolet wavelengths. This also holds true for infrared light, which has wavelengths longer than visible light but shorter than microwaves, rendering it invisible to the naked eye.

4. Does microwaving food kill nutrients?

No, microwaving food does not kill nutrients. There is nothing about microwaves that causes more damage to food than other methods of cooking. Indeed, microwaving has been shown to preserve nutrients. When vegetables are boiled, the soluble vitamins are leached into the cooking water, and food is cooked at much higher temperatures and for much longer periods of time in ovens.

5. Can microwaves cause cancer?

No, the microwaves does not cause cancer. Microwaves do not use x-rays or gamma rays, according to the American Cancer Society. Microwaves have no effect on the radioactivity of food. Microwaves can cook food, but their chemical composition remains unaltered and free of carcinogenic effects.

About the author

Colin Ma

An avid home chef, Colin is equally passionate about delicious meals as well as the latest cooking appliances. He's also a keen writer about cooking-related topics.


You may also like

Leave a Reply

Your email address will not be published. Required fields are marked

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}