Legal fireworks. :p

220...221...whatever it takes :D

I know pyrotechnics people alarm all the time. They tell me that they explain themselves before the are screened and it runs smoothly.

Whatever the hell that means. :rolleyes:

And that surprises you? :D

ETDs look for the high energy nitro bonds in high energy commercial explosives, like the nitro in trinitrotoluene, TNT.

Home use and even giant commercial fireworks are made from black powder, main ingredient the salt potassium nitrate. A low energy nitro compound which is less likely to be detected by the ETD.

The dark smudge is either burned or unburned charcoal, the ingredient that makes black powder, well, black.

The good news for you is that potassium nitrate is one of the most water soluble compounds on earth. One or two passes through the washing machine and there cannot be any left on your shirt to alarm. The black smudge, however, is another problem, as charcoal is not water soluble and even detergent will not do much to it get it off the shirt.

As for "I know pyrotechnics people alarm all the time. They tell me that they explain themselves before the are screened and it runs smoothly." This makes me feel real safe. Does this mean all a terrorist has to do is tell the truth "Good morning TSA, I work with explosives for a living, don't worry if I alarm" and they walk through?

I have an old, used missile engine casing around here. Perhaps I should take it on my next flight and see if it alarms or not. :) (non-metallic casing)

My typical laptop carry-on bag has contained recently fired handguns and also spent shell casings, and I've handled the bag after handing both and also having handled smokeless poweder, etc.

The bag, though swabbed several times, has never set off the ETD, fortunately. The moral of this story is that I doubt the fireworks device itself will have had much of a chance to really contaminate your clothes in a way that will alarm ETD.

These days, though, I do try to take better care of my current laptop bag to avoid the possibility of contaiminating it with explosives residue. I suspect a good wash or two separately from other clothing will do the trick. Cold or warm water, and I'd air dry it (particularly if you used alcohol or another flammable solvent on it at any point to try to remove the stain).

Soak the affected area with Coca-Cola. I've used that on my laundry many times, as it will remove most anything. And to think some of us pour this sugary, acidic beverage into our bodies.

Thank You!
 

I would like to thank everyone for the feedback, it is much appreciated.

This has actually been an interesting thread and it's great to hear the feedback everyone has had to offer.

In addition to items that will remove stains, I've learned how ETD machines are cleaned, that I'm unlikely to have an ETD issue (and more of an issue removing the stain), and that Spiff play's with legal fireworks (i.e. sparklers, snakes, and those small things that jump on the ground are the legal ones here :cool: ).

The fireworks display I saw was incredible (lets just say these probably were not legal fireworks) and even if the stain doesn't come out, it was a fantastic display. It's nice having a park (with a big open area) behind my house so that I can view the fireworks that others paid for :D It didn't make my day getting nailed by a chunk of fireworks debris, but ..it happens.

I am doing laundry tonight, so I'll find out if the stain comes out - and it sounds like I can rest assured it won't be setting off an ETD or Puff Portal. ;)

As said before, regular washing will get the water soluable nitrates out fine.

As for the fine particulate charcoal, using a stream of high pressure air from behind the marking (so if the outside of the shirt has the marking, shoot the air from the inside of the shirt out), so as to push the fine particulates out via the shortest distance (as per the old adage, how far can you walk into a forest? Halfway, as past that you are walking out of it) and not pushing it deeper into the weave of the fabric.

Essentially noone uses TNT anymore for anything (and it never was for fireworks nor commercial blasting) because it has a pretty high vapor pressure and so it contaminates everything it gets near to. Magazines that were used to store TNT cannot be used for anything else because the residual TNT will contaminate it. The only way to get rid of that is by "thermal decomposition" -- burning.

Steve