How Much Electricity Can Kill You?

Originally published at: https://boingboing.net/2020/09/21/how-much-electricity-can-kill-you.html

1 Like

It’s the size of the wave, not the “motion of the ocean”.

2 Likes

18 Likes

teacher-says-its-not-the-volts-that-kill-you-its-the-amps-and-i-be-like-watt

8 Likes

Professionally crafted, but the presentation is a bit too This American Life for me. Sloooowwww, languid narration…drawn out with music/sound effects, interspersed with a few very brief interview sound bytes. Had to listen at 1.5x to make the narration sound normal. For what seems is supposed to be a science-based show, the first segment has way too much pseudoprofundity “we all seem to have our own unique electrical field, which is why new touch can be kind of fun, you know.” “Here we are, a trillion or so Watts of current, swimming in a sea of fluid” (Watts of current?) Ugh.

For those interested, the electrical hazards portion (which the narrator qualifies by noting he’s unqualified, a fair cop, neither am I) starts at 12 minutes in.

The electrical dangers I find the most fascinating are not mentioned in the podcast at all and are from downed high voltage lines. When high voltage distribution lines touch the earth, the electrical field in the ground can be such that you can survive standing with your feet together on the ground, but if you take a step, the difference in electrical potential between where your feet are can be enough to kill you, going up through one shoe (not insulated enough for high voltage protection) up your leg through your heart and back down your other leg. The behaviors we are used to with 110 volt service doesn’t apply to high voltage. Our regular shoes are not protection from electrocution.

Back to the podcast: A caveat I would note is that the advice to not look for a breaker but to instead push someone away from an active electrocution with a dry wood pole is dangerous and can get the would be rescuer killed. I made this mistake during CERT training, where there was only a simulated casualty to deal with, and was I quickly admonished for suggesting the wood pole thing I’d heard about (probably from old articles and safety advice like that being read in the podcast) and not first seeking to turn off the power. You can’t rely on wood to insulate you from an unknown electrical hazard.

I don’t think that reading outdated magazine articles about electrical hazzards in a podcast without an expert to comment on any errors or potentially misleading information is a good idea. This is a slightly sketchy use of “vintage” source material.

10 Likes

Wasn’t the old saying:
" It’s the volts what jolts, but it’s the mils what kills."

To add to which- in most circumstances your skin is an insulator that tends to keep dangerous currents outside your body. try your best not to bypass it.

7 Likes

4 Likes

Caught my kid with headphones on about to stick the headphone jack in an outlet…

2 Likes

Is that still a current meme?

11 Likes
5 Likes

A 9-volt battery is plenty to kill you ^^’.

3 Likes

Cue obligatory bigclivedotcom video:

The surgical instruments I design are often used on or near the heart. There is a 10 µA (10 micro amp) leakage current limit when a several thousand volt DC potential is applied.

I also work on monopolar spray cautery instruments. They use 10 kV arcs to coagulate bleeding tissue tissue. But the frequency is above 100 kHz, so doesn’t affect nerves and is ‘safe’ around muscles such as the heart. They also have a 10 µA DC limit, despite several mA of AC.

9 Likes

Yikes! (glad they’re good)

Joke: Depending on the sound source that could have given them mono.

2 Likes

Even if it were, the text doesn’t even come remotely close to following the format associated with the image.

I’m just confused.

Depends where you stick it

1 Like

Man, what a cool comment - all of that. And regards to your work, Dioptase1! Curious how many devices you’ve designed, and if they’re all medical.

This would be the first time in my life I’ve read the grouped words “monopolar spray cautery instruments” in any arrangement, too. That’s genuinely awesome.

So you’re saying these are designed for high voltage contact but non-disruptive to heart rhythm?

Thanks. Yes, I’ve worked almost exclusively on medical products. Not all of them get commercialized. But it’s interesting work.

Most of my work has been with ultrasonic instruments. They vibrate at 55.5 kHz and use friction to both cut and cauterize. The concept is about 50 years old, but I made a patented breakthrough that is now used in hundreds of thousands of surgeries each year and is responsible for about 2 billion, with a B, in sales. This is an example of the product:

But other products on the market I’ve worked on include surgical staplers, bipolar instruments, and trocars. I’ve also dabbled in orthopedic, ophthalmic, vascular, bariatric, oncology, cosmetic, neural, spinal and emergency medicine products as a consultant or employee. Created a low cost non-sterile form of dialysis that is so cheap we couldn’t pursue it, so we donated it to a researcher.

Back to monopolar, none of my monopolar devices are on the market yet. But we have to prove compatibility. Thing like proving current from other products can flow through ours just as we are working on the heart. Monopolar can be foot activated and the instruments are often set near the incision for convenience. It’s shocking (no pun intended) how many OR fires and patient burns happen each year from accidental activation.

And yes, monopolar is supposed to be non-disruptive to the heart. It’s a brutal, but extremely cheap and effective, surgical method so not really suited to working on the heart. And I put “safe” in quotations because it’s surgery. There are always significant risks. Oh, and another cool thing about monopolar: it’s often used non-contact. It’s the arc to the patient that does the work. Think arc welding on a smaller scale. Depends on power mode being used. I tried to find a good video less than 20 minutes long and didn’t find one.

5 Likes

Fascinating! Thanks so much for the thorough reply.

My agony, it comes in spurts
I measure my pain in mega-hurts

Sufficient current through the heart kills; elsewhere, it burns. I was trained to work on power circuits with one hand safely in my back pocket.