Home Inspection

Clients ask me all the time - how dangerous is a microwave oven?

That's a very good question!  According to the Bureau of Labor Statistics, over 90% of homes in the United States have at least one microwave!  So it's a very ubiquitous appliance!

But, is it dangerous?  Can you get zapped by microwave radiation?

First we have to define radiation.

The "radiation" from a microwave is the same as comes from radios, TV, satellites, WIFI/wireless, radar and light.  It is electromagnetic radiation.  It's not the same radiation as would be experienced from an atomic bomb.  Microwaves won't make us glow in the dark!  They operate in the 2.45 GHz range, which is a low frequency and on the opposite end of the electromagnetic spectrum as gamma rays, X-rays and ultraviolet light.

But, the question remains, is a microwave oven dangerous?

Not really.

Microwave ovens work by causing friction between molecules.  The water in whatever is being heated is excited and heats up.

A microwave oven and the seal around the door is encased in what is called a Faraday Cage.  That is simply a metal mesh that absolutely prevents the microwaves from escaping the unit.  And the door is set such that if opened during the microwave operation the cooking waves immediately stop.

The United States allows some leakage from microwave ovens!  The standard is set at 5 milliwatts or less per square centimeter when measured 2" from the unit.  That amount is said to be less than harmful to humans.  Two feet from the unit degrades any leaking "radiation" 100 times, so the further one is from the unit the less the possible exposure.

In addition, the microwave electromagnetic radiation is non-ionizing.  Damaging radiation is ionizing, and causes cancer and radiation sickness due to molecular and DNA-string damage.  Too much ionizing radiation breaks the body down, sometimes quickly, and is dangerous and deadly.

There is, however, one kind of injury one can receive from a microwave oven.  And it's similar to what can be caused by cell phones.  Cell phones run at around 1800 MHz, similar to the microwave in the electromagnetic spectrum.  Ham radio operators used these same high frequencies.  The danger to them was not cancer but heat related.  Used a lot, the ham radio Ultra-High Frequencies (UHF) can cause minute increases in temperatures to eye tissue.  The eye has no heat-regulating mechanism.  There is not as much circulation of blood in the eye, which can move around and carry off heat, so it is subject to damage.  The heating of the eye over time can cause cataract formation.

The other microwave danger is fire.  The water in whatever is being cooked is what heats up.  If there is not much water or if the water in the cooked material evaporates, things can heat up too much.

Also, metal in the microwave can cause arcing.  Who hasn't heard that one?  Stainless steel does not cause such arcing however.

And no matter what is cooked, or what it's in, microwaves can heat unevenly.  But again, who doesn't know that!?

My microwave test in a vacant house is to put a little wet paper or toilet paper in the unit for 10 seconds.  If it heats in 10 seconds or so the unit is operating properly.

So, what to do?

For safety, merely stand 2-4' from the unit when something is heating up!  Like was said above, microwaves are just that - micro!  The further from the unit the more degraded the "radiation" becomes.  And therefore, if there is any danger, it is significantly reduced! But really, the Faraday Cage works as advertised and makes the unit very safe!

Still, if you should have a radiation concern, microwave radiation detectors can be purchased and are not expensive.  Keep it in the kitchen cabinet drawer!  Two detectors of the most popular detector brand are here and here.  And they both have built-in alarms.  The second link is a little cheaper and has the highest consumer rating.

My recommendation:  have a microwave oven and enjoy it!  Over 90% of households do!  Make sure the unit is in good condition and closes properly.  And if you have concerns, just turn it on and move away to do something else.  And remember, what comes out can be very hot, so you are warned herewith and don't sue me if you spill hot chocolate in your lap.