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Butcher · 05-07-2005, 10:07 PM

I draw to your attention:

http://web.mit.edu/environment/ehs/e...echanical.html

In particular:

Code:

CURRENT IN MILLIAMPS   EFFECTS OF 60 HZ CURRENT PASSING THROUGH THE BODY  
1 or less              May not be felt - Maximum harmless intensity 
1 to 8                 Sensation of mild shock, can let go at will  
8 to 15                Painful shock, muscles contract, may still be able to let go  
15 to 20               Painful shock, can NOT let go  
20 to 75               Intense pain, breathing may be paralyzed  
100 to 200             Ventricular fibrillation; holds unconscious victim to the circuit, could be fatal  
200 or more            Heart stops, muscles contract intensely & could break bones, severe burns, breathing stops

Please note that according to this data a shock under 1mA (such as one in the microamp range) is considered harmless and is unlikely to be felt.

I'm more inclined to believe MIT's safety page than you frankly. Especially given that even the briefest of google searches turns up numbers in the 20+ mA range as the lethal current for humans.

I would like to add that the typical finger to finger resistance of the body excluding skin is 1000 ohms, hence the 30 (or 40) volt warning as a safety precaution - it is the minimum voltage to get a lethal shock at (outside of jamming electrodes into the heart). 30V, 1000ohms gives 30mA current, though to actually get the resistance that low you would need wet hands or some other means to massively lower the skin's resistance.

05-07-2005, 10:07 PM	#19
Butcher Thermophile Join Date: May 2001 Location: UK Posts: 1,064	I draw to your attention: http://web.mit.edu/environment/ehs/e...echanical.html In particular: Code: CURRENT IN MILLIAMPS EFFECTS OF 60 HZ CURRENT PASSING THROUGH THE BODY 1 or less May not be felt - Maximum harmless intensity 1 to 8 Sensation of mild shock, can let go at will 8 to 15 Painful shock, muscles contract, may still be able to let go 15 to 20 Painful shock, can NOT let go 20 to 75 Intense pain, breathing may be paralyzed 100 to 200 Ventricular fibrillation; holds unconscious victim to the circuit, could be fatal 200 or more Heart stops, muscles contract intensely & could break bones, severe burns, breathing stops Please note that according to this data a shock under 1mA (such as one in the microamp range) is considered harmless and is unlikely to be felt. I'm more inclined to believe MIT's safety page than you frankly. Especially given that even the briefest of google searches turns up numbers in the 20+ mA range as the lethal current for humans. I would like to add that the typical finger to finger resistance of the body excluding skin is 1000 ohms, hence the 30 (or 40) volt warning as a safety precaution - it is the minimum voltage to get a lethal shock at (outside of jamming electrodes into the heart). 30V, 1000ohms gives 30mA current, though to actually get the resistance that low you would need wet hands or some other means to massively lower the skin's resistance. __________________ Once upon a time, in a land far far away...