When discussing safety of electricity, one usually considers a constant DC or AC current with constant amplitude over a longer time. It is easy to find tables in books or in the web which lists different magnitudes of current and it's physiological effect on the human body. For example this (chest pathway):

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If you consider a short time discharge, for example from a capacitor or an inductor, this description no longer applies. For example if you charge a small parallel plate capacitor with several thousands of volts and touch it, nothing dangerous will happen (just a slightly painful sensation). Initially the current through the body will be very high (such that it would be deadly if it was constant), but which decays exponentially in a very short time.

So one needs another scheme to evaluate the dangers to the human body in the case of a short discharge. One simple criterion is the energy criterion where one calculates the energy which may maximally deposited in the human body by the discharge. This is for example used in for electrical safety guidelines for German schools (http://publikationen.dguv.de/dguv/pdf/10002/si-8040.pdf, page 27), where for > 60 volts a discharge energy below 350 mJ is considered as safe.

My question is if there exists also an overview of the effects on the human body for short discharges depending on the energy (for the case of > 60 volt), or even a two dimensional map (one axis voltage, the other one energy).

If so, do you have a reference to the original papers.

  • $\begingroup$ Is there any source claiming that capacitor discharge with thousands of volts is not fatal? $\endgroup$ – JM97 Mar 13 '17 at 15:47
  • $\begingroup$ @JM97: I tested it several times. But be aware, that this only works, if the discharge energy is low enough. Take for example the 350 mJ limit I cited in my post. Below this it should be safe. Then take a parallel plate capacitor without dielectricum, plate distance say 0,5cm and a square plate with $0,25\cdot 0,25 \,\mathrm{m^2}$ area. Then you get a capacity $C = \epsilon_0 \frac{A}{d} \approx 1,1\cdot 10^{-10} \,\mathrm{F}$ and with $U = 500\,\mathrm{V}$ you get a discharge energy of $E = \frac{1}{2} C U^2 \approx 1,38 \,\mathrm{mJ}$. $\endgroup$ – Julia Mar 13 '17 at 16:11
  • $\begingroup$ However take another commercial capacitor with say $1\,\mu\mathrm{F}$ capacity, then at $5 \mathrm{kV}$ you get $12 \, \mathrm{J}$ as discharge energy. I guess this would be fatal (don't worry, I am not going to test this :-)). $\endgroup$ – Julia Mar 13 '17 at 16:16
  • $\begingroup$ If there is more transfer of charge in less time that is higher amperes of current is passing then it will be fatal not only due to its effects on membrane charges but also due to intense heat produced by the fast moving charges. So the tables given in question are enough $\endgroup$ – JM97 Mar 13 '17 at 16:21

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