Sciencemadness Discussion Board

does flash powder make nitrogen dioxide when burning?

BauArf56 - 25-5-2021 at 07:01

i used to use the yellowish flash powder which is inside ice fountains (those candles that make big flames and sparks) for making little rockets. I just wrapped it in tin foil and heat it up till they ignite and fly. I usually noticed that trail of smoke made is yellowish and has a pungent smell similar to sulfur dioxide, but a bit stronger. Could it be NO2?

ShotBored - 25-5-2021 at 08:24

Without composition it's hard to tell. There are dozens of types of flashpowders and formulations. Flash powder is not what you would put inside rocket motors. Just to clarify.

Typically what is inside ice fountains that I've seen nowadays is nitrocellulose with Titanium granules. Maybe some other components to get some more heat or burn time. NO2 would be reddish-brown, could appear yellow though. I've seen it offgas from decomposing Nitrocellulose many times and has a very pungent and acidic odor that can be toxic. If you're heating ice fountain comp up in tin foil instead of instant decomposition via lighting it, the composition would certainly be releasing NO2.

BauArf56 - 25-5-2021 at 09:01

Quote: Originally posted by ShotBored  
Without composition it's hard to tell. There are dozens of types of flashpowders and formulations. Flash powder is not what you would put inside rocket motors. Just to clarify.

Typically what is inside ice fountains that I've seen nowadays is nitrocellulose with Titanium granules. Maybe some other components to get some more heat or burn time. NO2 would be reddish-brown, could appear yellow though. I've seen it offgas from decomposing Nitrocellulose many times and has a very pungent and acidic odor that can be toxic. If you're heating ice fountain comp up in tin foil instead of instant decomposition via lighting it, the composition would certainly be releasing NO2.


know it, unfortunately it's almost impossible to know exactly what's in the mix. How do you know it's titanium / nitrocellulose? it could be, as it burns very quickly and gives off whitish sparks, so it's very interesting. Anyway i use it because this is the best powder for rockets, as it doesn't tend to explode if confined, but to give off a lot of gasses and propel the container.

ShotBored - 25-5-2021 at 09:15

It's a hunch, as I work in the industry. Ice fountains are similar to other things I have worked with. If, when burned in the ice fountain, the effect is mostly smokeless, then there is a good bet it is Nitrocellulose and titanium, however zirconium for sparks is a possibility. It's usually cost-prohibitive though.

But it's not surprising about its use in rocket motors. Nitrocellulose is used in single- and double-base propellants often.

Deathunter88 - 25-5-2021 at 10:35

ShotBored is right, ice fountains have nitrocellulose, not flash powder.

BauArf56 - 25-5-2021 at 11:32

nitrocellulose was the last thing i expected from those fireworks! maybe i could exploit the NO2 generated for making nitric acid...

Fulmen - 25-5-2021 at 11:36

Indoor pyrotechnics are usually based on nitrocellulose due to health and safety. As the OP has noticed it can give off some NO2 during combustion.

ShotBored - 25-5-2021 at 11:47

The process for removing nitro-groups from organics is likely documented somewhere on here, however I highly doubt you'll be able to just strip the nitro group off easily. Nitrocellulose is notoriously unstable: it is always slowly decomposing and it's decomposition is auto-catalytic. This problem has a large history of industrial and amateur accidents to back it up. Almost all nitrocellulose-containing pyrotechnics nowadays contain a stabilizer to prevent this decomposition.

Typically, the removal of nitro groups from similar compound such as nitrobenzene rely on converting the nitro group into an amine, then an azide, then using hypophosphoric acid which offgasses N2. The army had a patent for nitrocellulose waste back in the day...they used thioerythritol or something, but I can't find it right now.

BauArf56 - 26-5-2021 at 03:52

Quote: Originally posted by ShotBored  
The process for removing nitro-groups from organics is likely documented somewhere on here, however I highly doubt you'll be able to just strip the nitro group off easily. Nitrocellulose is notoriously unstable: it is always slowly decomposing and it's decomposition is auto-catalytic. This problem has a large history of industrial and amateur accidents to back it up. Almost all nitrocellulose-containing pyrotechnics nowadays contain a stabilizer to prevent this decomposition.

Typically, the removal of nitro groups from similar compound such as nitrobenzene rely on converting the nitro group in an amine, then an azide, then using hypophosphoric acid which offgasses N2. The army had a patent for nitrocellulose waste back in the day...they used thioerythritol or something, but I can't find it right now.


ugh... seems much harder than i thought. Since i don't know much organic chem i thought that i could treat it just as a normal inorganic nitrate, so by adding a strong acid some nitric acid could form, but obviously it's much harder. That method (nitrate to amine then azide) is definetely out of reach for me because i'm not skilled in that kind of stuff. Maybe heating nitrocellulose carefully with sodium bisulfate could release some NO2?

[Edited on 26-5-2021 by BauArf56]