Current and Voltage Effects on Human Body

Electric Shock

In my last post about Electrical safety, I talked about the Electrical hazard and the reason behind it. Now I will talk about the Current and Voltage Effect on Human Body.

Let’s start with the human body. Human skin resistance varied from 400 ohms for wet skin to 500000 ohms for dry skin. That’s means when you are wet then your body skin resistance will be 400 ohms and when your body skin is dry then your body resistance will be 500000 ohms.

The fatal voltage for a human body is 40 Volts and above. Considering 100mA as fatal current and 400 ohms as body resistance, the voltage may be calculated by this equation

V=0.1×400=40 Volt

If the body having higher resistance then the damage will be lower. This may be attained by using rubber gloves, rubber mats and like others. The duration of passing current through the human body is too much important.

A sudden shock of 15 to 20mA for just 10 sec or longer then the person will feel a painful shock and muscular control effect, but cannot let go. That means the voltage and current through a normal human body is always less the 40V and 15mA.

Now here is a chart for the current effect on the human body and it will give you a strong idea of human body damage when there is a sudden electrical shock happened.

The magnitude of Passing Current	Effect on Human Body
1 to 8 mA	Perceptible, But not Painful
8 to 15 mA	Painful Shocks, But Muscular Control is Not Lost
15 to 20 mA	Painful Shocks, Muscular Control Affected, Cannot Let Go
20 to 50 mA	Severe Muscle Contraction, Breathing Difficult
50 to 100 mA	Serious Contraction of Heart Muscle, Possible Death, No known Remedy
100 mA and above	Severe Burns, Stoppage of Heart, Death Certain