Naked Science Forum

General Science => General Science => Topic started by: thedoc on 01/08/2013 21:30:01

Title: Are static shocks harmful?
Post by: thedoc on 01/08/2013 21:30:01

"dmalothane29 asked the Naked Scientists:
   
Is static electric dangerous to a human?

I work with these isolation boards made of polystyrene. They shock like hell; sometimes you won't knock off from work without being shocked. The reason why ask is because the shock gives me a long-term shake.

Regards
Danile malothane
In South Africa

What do you think?

Title: Re: Are static shocks harmful?
Post by: RD on 01/08/2013 23:50:49

Grounding straps and anti-ESD (https://en.wikipedia.org/wiki/Electrostatic_discharge) footwear is available to prevent you becoming charged ... https://www.google.com/search?tbm=isch&hl=en&source=hp&biw=&bih=&q=esd%2Bshoe%2Bstraps&btnG=Search+Images&gbv=1

Don’t improvise a grounding strap with a bit of wire. The store-bought versions have electrical resistance built-in as a safely measure : to prevent you from receiving a serious electrical shock if you stood on an exposed live mains-electricity cable wearing one.

Title: Re: Are static shocks harmful?
Post by: evan_au on 02/08/2013 11:29:58

Large quantities of static electricity (eg being struck by lightning) can be lethal.

But the ordinary little zaps you get from wearing synthetic clothes or plastic-soled shoes on a dry day are more a nuisance to a human.
On the micro scale, these small electrical discharges are very hot, and probably kill skin cells where they strike, and may damage surrounding cells by perforating the cell wall, perhaps letting in viruses and bacteria (the already-dead outer layer of skin cells will provide some protection against these biological attacks).

Grounding the work area and the worker, and/or increasing the air humidity should reduce the number and severity of these nuisance static discharges.

Title: Re: Are static shocks harmful?
Post by: allgoaway on 28/08/2013 04:59:57

It all comes down to the amperage of the static shock, here is a list from an electrical text book. 0.001A (1 milliamp) or less is felt slightly as a tingle,  0.001A to 0.01A (1 to 10 milliamp) would probably cause muscles to contract and prevent releasing the object, 0.01A to 0.1A (10 to 100 milliamp) fatal after several seconds, and 0.1A or more (100+ milliamps) almost always fatal. So I would go with what RD said and get yourself some personnel protective equipment.

Title: Re: Are static shocks harmful?
Post by: Bored chemist on 28/08/2013 19:48:02

The sort of shock you get from static electricity isn't harmful in itself, but the annoyance may not help your blood pressure any.
If you can't do something to prevent the shock, you can often lessen it by making sure that the spark jumps to a metal key or coin held in your hand, rather than directly to the skin.

Title: Re: Are static shocks harmful?
Post by: evan_au on 30/08/2013 11:46:10

Static shocks are extremely harmful in coal mines.
There is often methane around (less of a problem with today's ventilation systems).