Is there something safer available which does the same thing? I used to use some sort of flash powder for theatrical effects but this was twenty years ago and I can't remember what it was (if I ever knew).
Steve.
Ah, yes, the good old stage flash powder. I'm pretty sure it's identical. I once worked briefly as a lighting tech, and the ASM wouldn't let me set the flash-boxes myself (it was in panto in the late 60s). Unfortunately he didn't know how to set them (I did): he thought that if one turn of fuse wire was good, several turns would be better. Nor would he let me fire them: he kept control of those switches.
After the show, when only 2 out of 6 had fired, he went and poked the first of the unfired ones with a screwdriver. He wasn't badly hurt, but he was a bit short on eyebrows and the hair at the front of his head was frizzy and smelled funny.
Much as I am aware of the dangers of the stuff, I have made it (not in almost 40 years -- around the same time I learned how to make napalm and thermite), and I can't help feeling that like many things of that kind, it's not all that dangerous as long as you remember that if you get it wrong, it's VERY dangerous: a bit like firearms. Our ancestors lived with a lot of things that would be regarded as horrifyingly dangerous today, such as flash powder and for that matter simple gas-taps: we had those when I was a boy. Yes, there were accidents, but there was not the wholesale slaughter that you might expect from reading modern-day warnings.
Addition: a reminder from the Focal Encyclopedia 1965:
Commercial flash powders are supplied in double containers. One holds the magnesium powder, the other, the igniting compound...