Re: At what point is electricity dangerous - Scientifically?

You are correct that anything over 20 ma is considered potentially fatal. However, under certain circumstances as little as 12 ma can be fatal.

Also, according to ohms law I=E/R. So if your body has a 4 k skin resistance ( dry skin, low salt ), then it takes about 40 volts to generate 10 ma but generally unless the electric source is current limited, anything over 12 volts is considered potentially dangerous.

Wet sweaty skin can have a skin resistance of less than 1 k ohm so that a 12 volt battery can generate 12 ma of current through the body ( enough to kill if it follows the right path ). It can get worse though. Once the voltage breaks down the skin resistance, it can cause chemical reactions that further reduce the skin resistance which can further increase the current.

BTW, static electricity generated from walking across the carpet can be well over 50,000 volts but the current is small, usually only a couple of ma.

The body normally feels currents over 4 ma.

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