How dangerous are blasting caps?

Blasting caps contain a small amount of sensitive high explosive material and a triggering mechanism, and are used to cause the detonation of a much larger amount of less sensitive high explosive.

Question: how dangerous are blasting caps themselves? If I hold one in my hand while it detonates, will I reliably:

-shred a couple of fingers?

-lose a hand?

-lose an arm?


1962 or thereabouts, a family friend (boy, 12yrs) and some pals found blasting caps in an unlocked shed. He picked one up, it exploded in his hand, he lost the first two fingers (completely gone, no stubs or remnants) and much of the thumb.
I have no idea if blasting caps are much different 50 years later.

When I was a kid, they had a lot of public service ads about how dangerous they were. I think I remember one with Willie Mays saying, “Remember kids, don’t touch them.” Haven’t seen one in many years.

When I was a kid in the 80s they mentioned them as things to avoid, but I didn’t actually know what they were to the point where if I found one I would know what it is until much later.

Don’t Touch Blasting Caps!.

I used to work for a powder monkey and still work with ordnance (mostly in the form of cartridge-actuated devices, linear shaped chargers, and similar cutting and severing applications). While all ordnance and energetic materials need to be treated with caution, it is really only blasting caps and electroexplosive devices (EEDs) which have any real likelihood of going off under casual handling conditions, especially due to electrostatic discharge. Whereas a block of C-4 plastic explosive can be dropped, torn, set on fire, struck with a hammer, and shot with a rifle without going off, a #8 blasting cap will reliably set off a 1/2 kg block of C-4 to complete detonation. If you held one securely in your hand, my educated guess is you’d be left with a stump of a palm.


When I worked in a mine, the training program demonstrated blasting caps by putting one in an aluminum pop can and setting it off inside a thick capped steel pipe, about 5 inches diameter and four feet long. First, it was incredibly loud. Second, it shredded the pop can. Finally, the blasting cap is made of metal with explosive inside. High-speed shards of metal are certainly dangerous on their own (You’ll shoot your eye out!)

Back in 1970, when I was in 5th grade, a student in another class came to show-and-tell with what he thought were bullets, but were actually blasting caps. He passed them out to his classmates, who found that blowing into the caps made a whistling noise. One of the boys couldn’t get his to whistle, so he tried cleaning it out with the point of a compass. He lost a couple of fingers. They were successfully reattached later, though, thanks to an intrepid gym teacher who retrieved the fingers and packed them in ice.

A number of years back, some 5th-6th graders found some caps at a construction site and took them to school. No one was hurt, but I can still see the pictures of the caps with teeth marks in them where the kid was trying to chew it open to get the powder out.

Ye. Gods.

In the mid-70`s some kid took a pliers and pulled the rods out of 9 volt batteries and tossed them around the hallways of the school I went to. They must have looked enough like blasting caps to convince school officials as they freaked and closed the school so it could be searched by the local police.

When it turned out it was just battery rods everyone r:rolleyes:lled their eyes until a girl found actual caps at a railroad construction site and assumed it was nothing to worry about. After surgery she still was without most of her right hand.

Have detonators gotten any safer over the years? It seems logical to phase out the kind with sensitive explosives in favor of ones with a more difficult trigger mechanism. For instance, the exploding-bridgewire detonator is be virtually impossible to set off without sophisticated equipment (certainly impossible with classroom handling). I’ve no idea if this type is in common use; perhaps the equipment is too expensive to be practical in most cases.

One safety test the mines engineers did was to hang the electric caps off the antenna of a walkie-talkie to demonstrate that contrary to signs posted near road construction, “use of radio” will not set off modern blasting caps.

Of course not directly, but what if they are using radio transmitted signals to remote equipment detonating them?

Still no. At least not since awhile. You’d have to have the transmitter tuned to the frequency of the receiver, using whatever modulation it would be using, and any communication protocol. At least anything within the last 30 years I would imagine.

The type of device you describe would be very very old, when radio was new, and running out long lines of wire was more impractical/costly than using wireless. And, simply keying at the correct frequency would cause the receiver to latch in some way and connect the power source to the blasting cap.

Going by my USN experience, my WAG, a lot of this precaution came about WWII. There were some great leaps in tech then and I think this is when they truly realized the potential of accidental detonation/ignition and made steps to prevent it. They probably realized that having the “bomb farm” right next to a high power HF transmitter would eventually cause something to go off. I’m guessing some excited dissimilar metals in combination with salt air/humidity and then a prolonged electric field: BOOM.

Wow. Can firecrackers do as much damage? It seems odd firecrackers are regulated but blasting caps are just lying around.

I remember the PSAs well. I never understood why they would be just laying around. You don’t leave dynamite laying around, or bullets. Even a kid knows that.

There must have been a series of tragedies to produce so many PSAs.

People used to be fairly casual with explosives, and because blasting caps are so sensitive (and previously were often not marked with lot numbers or expiration dates despite being aging sensitive) they pose a much greater hazard than dynamite, Seismopac, or Emulex.


Anywhere men do work outdoors they drop things from time to time. Which they may not notice immediately. Or which fall in the snow or mud & can’t be readily located. So they shrug their shoulders & go back to work.

6 months later some kids are playing around what had been the construction site. And they find the various dropped nails, bolts, soda cans, etc. And the blasting caps.

In some parts of the country explosives are rarely needed in construction. In other areas the soil conditions are such that no good-sized building gets built without at least some blasting. It’s that latter case where BCs are common enough in construction litter to mention.

There it is, that makes sense. Yes, growing up in the west, blasting was really not needed at all.

I remember the same PSA from when I was a kid. I still remember how he pronounced ‘don’t touch them.’

And in some areas, small home gardens can’t be dug in without blasting. :smiley: