There are two dangers with microwave ovens.
1) Take the cover off and try and work on it, without
appropriate precautions.
2) The danger people don't seem to be aware of, is if
the capacitor arcs over, while the microwave is
cooking your lunch.
I was present for a (2), and the noise was loud enough,
I lost hearing in one year for ten minutes. I thought at
first I was fucked, and had a popped eardrum or something.
But the ear eventually started coming back.
The root cause in that case, is too many people at work
cooking bag after bag of salted buttered popcorn. This
coated the inside of the machine with conductive material.
Modern microwave ovens can have things like conformal
coatings to try and prevent this.
Strangely, the microwave oven was not damaged, and it
was still run-able the next day.
*******
The problem with the microwave, is the potential energy.
1/2CV^2 on the oil-filled cap, is a significant number.
It's three times the energy need to fire a
dye pulse laser.
And that's why, if and when it discharges, while fully
loaded, you don't want to be standing close to it.
That's the old style transformer-diode-cap 50Hz design.
The modern inverter design might have different safety
characteristics. Even though the inverter design is better,
companies *still* make the legacy kind.
*******
HV arc discharges release ultrasonic energy. One of my
chem profs at uni, was deaf in one ear, and all because
he did not wear hearing protection while working on
pulse lasers. He'd be the first guy to warn you about
the dangers of "many, smaller discharges" on hearing.
There was a second prof, who used to blow up shit behind
a perspex barrier (we don't know why), and his hearing
was a bit bad, but he still wasn't wearing protection.
He used an arc to "dispatch" stuff.
Those are my favorite kinds of elfen safety examples,
the walking and still-breathing kind. You can point to that
and say "this is why we wear hearing protection" :-/
But this is what happens when an elfen safety issue
takes a lot of attempts, and the degradation is slow
and steady. You can be tricked into not wearing protection.
To this day, when I start a microwave oven... I walk away.
I wonder why that is... I don't want to experience that
a second time.
Paul