Sorry I havent a refrence but I have heard that at least 3 people a year have cardiac arrest becouse of this. From the internet: Now, the explanation I have heard as to why this is, is that in certain freak cases, the battery can make an almost direct connection to the nervous system where the nerves are close to the surface and the skin is wet, thus ionising the nerves so that they will not work correctly. Result is death.

The detractors who attempt to answer this question invariably end up quoting figures for levels of current which kill then stating that a batter cannot generate these levels of current. This basically just dodges the issue since we have a fairly specific set of circumstances and it is not claimed that the current actually kills, rather the effect of a DC potential connected directly to the nervous system.

Besides, the figures quoted are guidelines for safety and not intended to be an absolute guarantee of safety. It is also my understanding, having spoken to a number of older electrical engineers, that there were different figures quoted for lethality for DC voltages and AC voltages, with the level of DC being significantly lower than for AC.

Coincidentally, someone asked me about this last night. I couldn't find anything on Pubmed
Careful with figures found on the Internet, many of those state touch current ie with intact [keratinised squamous epithelium] skin a different histological ball game from glossal or buccal tissue.

I asked a consultant vascular surgeon I know about currents required for cardioversion when elec safety regs for medical [strictly speaking medico-chirurgical] locations were being developed, he stated only microamps were required to effect cardioversion in an anaesthetised Pt.

I daren't ask on the IET now since the membership requirements were lowered and the provenance of responses in often now very questionable.

I wonder whether any of these deaths [*which I can find no references to*] were by nervous sytem pathways CN IX, X, XII, eg by directly affecting vagal tone ?

I know of IEC TR2 60479 1 and 2 Effects of current on human beings and livestock general aspects/special aspects.

Not sure if I can access this at the med school library.

No the IEC document is not accessible.



Nothing in MBChB or BBMS standard cardiology texts in heavy demand with anything definitive regarding physiological effects of DC or AC current levels. Didn;t check in the emergency medicine texts but they are few and far between, nor neurophysiology texts (no time). Nothing in Vanders

I checked a couple of reference manuals including a weighty Biomedical Engineering one. 

Roth, Wikswo, Henriquez 93, Clerc T Phys 255:535 (1976) Roberts et al, Roth Ann Biomed Eng 16:609 1988, Roberts et al Circ Res 44(?):701 1979  Roberts and Scher Circ Res 50:312 1982 I have scribbled down but haven't consulted even to see if they are relevant and they are all pretty old in biomedical research years.

I'm sure I jotted down physiological impedance values from the BM Eng ref manual but I can't find my jottings.



I doubt there would be (m)any controlled studies on electric shock, well not with human datasets for obvious ethical reasons. Not sure how well animal characteristics would extraolate to human tissue.



IET Rufaie 2010 in a seminar verbally cite a professor Begelmeyer in Austria with recent studies. Can't find any studies on the web attributed to this Professor (of what) but as citation was verbal I'm not sure if I spelled the Professors name correctly.



Sorry, didn't have time to go upstairs to the other floors to check the periodicals and non-heavy demand.



There are a lot of varying figures  around [there are associated time and frequency curves] but I' they never seem to be quoted with citations.

For ac they would indeed normally be quoted as RMS not Pk-Pk.

  

If you take say a RCD device for electrical garden tools. These have a trip of about 30mA and take 50 ms to disconnect. You will feel a shock, but it is unlikely to be lethal. If I recall it can be up to 100mA and 400 mS disconnect time. ( Information can be found in BS7671 wiring regulations)



I can’t see any problem with 9v batteries, I’ve tested these on my tongue since I was young.



I am however aware of children swallowing the small ‘button’ batteries. These contain cadmium and other heavy metals. Typically these pass through the body without causing harm. But swallowing such a device should be considered as an emergency to be checked out at hospital.

I can’t see any problem with 9v batteries, I’ve tested these on my tongue since I was young



I wouldn't recommend that. They say it stunts your growth!