Electric Shock: Dos and Don’ts
Sort of a counter post to my previous one on some peculiar ideas about electricity
Let’s begin with mediocre metaphor: using electricity unsafely is a bit like arterial hypertension, one may live for while not knowing the danger one runs, until the day ill-founded confidence outruns it’s course and one ends up either seriously ill or dead. There is a common disregard as to the seriousness of both, as well as ignorance and reluctance to consult a specialist.
So here are some notes I gathered on electricity related safety:
- OSHA (Occupational Safety and Health Administration) in US found that up to 80 percent of its electrical injuries involve thermal burns due to arcing faults (arcing fault being high power discharge of electricity between conductors)
- electric arc of sufficiently high voltage does not require a physical contact, as it may “jump” the air gap; in fact, energy released may seriously damage or kill at distances up to 6.1 meters
- electric arc can be used in well controlled conditions and are, in fact, in arc lamps used in welding
- there are several signs and symptoms of electric shock:
— burns (pretty straightforward, but it should be noted that internal damage may be more serious than the external injuries indicate)
— ventricular fibrillation (ventricular fibrillation is a cardiac rhythm disruption characterized by haphazard and disorganized heart contraction leading to inability to pump blood, which in turn leads to cessation of circulation, which is fatal, if not corrected by using defibrillator)
— effects on nervous and muscular systems (pain, tingling, numbness, losing consciousness, severe muscle spasms and tears, seizures, and respiratory arrest
— arc-flash hazards (arc flash is light and heat produced from an electric arc formed at high voltages that has enough power to cause fire, injuries and generally wreak havoc)
- arc flashes can produce deafening noises, supersonic concussive-forces, shrapnel, extreme heat (19,400 C versus 5,520 C of Sun’s surface), and intense, high-energy radiation capable of vaporizing anything close to it (example given in Wikipedia is copper vaporization that leads to it’s expansion by a factor of 67,000 in volume)
- arc flash also produces ionized particles and plasma that could severely damage respiratory system; plasma could be attracted to any metallic objects nearby (jewelry, eyeglasses), burning the surrounding skin as well
- arc flash is more likely to form in a switch that is closed slowly, by allowing time for an arc to form between the contacts, so it is usually more desirable to “throw” switches with a fast motion
- current above 10 mA going through flexing muscles in the arm and forearm could give one a sustained contraction, which makes the injured unable to let go, thus prolonging the contact and increasing severity of injury
- similar stimulation triggering violent contraction to hip extending muscles (extending your legs away from the body) could thrust the victim a few meters away
- National Coroners Information System (NCIS) in Australia indicates that between 2000 and 2011 there had been 321 fatalities with the cause of death being electrocution, but probably much more people get shocked in a non-fatal way on day-to-day basis with varied degrees of consequences
Now getting to the Prophylactic Basic Tips (most of them are in a “Duh, of course” category, but just in case)
— never use a damaged extension cord or a defective electrical device
— pull on the plug and not on the cable to unplug an electrical device
— before changing a lightbulb, switch off the light or unplug the lamp, or better still shut down the power in your place
— unplug the device before handling it eg to dislodge a stuck toast in a toaster, or pouring water into the iron
— make sure to locate electrical wires before drilling a hole in the wall
— be careful when using multi-outlet bars. Connecting too many devices that consume a lot of electricity could lead to overheating.
— in the bathroom, never use electrical devices if you are wet or the humidity level is high
— do not use electrical devices or extension cords near a pool
— do not cut off or bend the third prong of a plug
— never throw water on an outlet that’s on fire
If someone got shocked
— do not touch the victim (it is said that one thing, that paramedics and first responders dislike more than one corpse, is two)
— raise the alarm, call for help
— separate the person from the source by either cutting the power off at the source (if you can do it without endangering yourself), or if unable to do so, stand on something dry and non-conductive (a book, wooden board, or wearing shoes with rubber soles) and try to separate the victim from current using non-conductive object (wooden or plastic broomstick, wooden chair or rubber mat)
— with high voltage lines involved, the power company must shut them off; if you feel tingling in legs or lower body, do not try to separate the victim from current, instead hop on one foot to a safe place (at least 6 meters, and further, if wires are jumping and sparkling) and wait for the power to be shut down;
— if power line fell on the car, stay inside as the rubber tires would serve as an insulation, unless there is a threat of explosion or fire (in which case, when getting out, keep your feet close together and jump away, not walk)
— all wires should be treated as if they are live
— when it is safe to touch the person, check their airway, breathing, and pulse, then proceed to perform first aid to keep injured safe and alive until medical aid arrives:
- person is conscious but faint, or pale, then lay her down with her head lower than the trunk and legs elevated, and cover with something for warmth
- person is conscious, breathing steadily and responsive, but has burns: cool the burns under running water for 20 minutes and cover with dressings, that won’t stick (cling wrap would do, applied not too tightly); never put oil or ointments on burns though
- person is unconscious but is breathing, pulse and heartbeat are perceptible: lie the victim on a her side to prevent choking
- person is unconscious and not breathing, but has a pulse: start the respiratory assistance at once, preferably using mouth-to-mouth method
- person is unconscious, not breathing and has no pulse: begin CPR maneuvers
Finally, consider taking a first aid course or at least CPR part of it, and be sensible. Physics rules our world and she is a strict mistress. As the most beloved and well known Soviet-Korean singer Victor Tsoi sang: “Look after yourself, be careful”. Well, of course he did it in Russian, but nevertheless.
Sources:
https://www.betterhealth.vic.gov.au/health/healthyliving/electric-shoc
