ionized radiation - microwave oven?

Question

I understand that microwave ovens emit non-ionizing microwave radiations which are of no harm to health

But some medical instruments use ionizing microwave radiations

Also, I read that ultraviolet rays are ionizing radiations which cause cancer. Hence long time exposure to ionizing radiation is bad.

Is there a possibility of microwave oven, due to overuse and bad condition, might emit ionizing microwave radiations?

Answer 1

The oven does not emit any significant amount of ionizing radiation. The only element in there that can produce x-rays is the magnetron because it accelerates electrons to approx. 6000V. While the current is quite high (hundreds of mA), the low energy x-rays that are being generated will not make it out of the metal housing of the oven and probably not even come out of the magnetron tube.

Having said that, an old style color tv with a CRT runs on 24kV acceleration voltage at a few mA of beam current. While the front of the CRT is pretty thick glass and x-rays are Bremsstrahlung and therefor preferentially emitted perpendicular to the e-beam direction, there is a measurable x-ray flux from a CRT.

I did go on a radiation hunt with a very sensitive lab radiation monitor once and found exactly one source that was slightly higher than background: my computer monitor!

Among the worst x-ray sources, however, are AM transmitter station amplifier tubes and magnetrons for aircraft radar because they run at much higher voltages (around what the x-ray tube in the doctor's office works with) and with beam currents of A, not mA. There have been very nasty accidents when technicians disabled the power supply lockout circuits to work on the equipment while it was operational. People have gotten radiation burns and died of cancer years after these accidents.

Answer 2

No, the frequency is to low to ionize atoms. Solving this problem was how Einstein started quantum physics.

Notwithstanding, microwave radiation is dangerous. If it can cook food, it can cook you. (Some of the more sensitive cells are in the eyes and the sperm). It can also cause problems for metal objects such as pacemakers, etc.