9 replies to this topic

[Sparky]

Hey all

 

I've just seen the news item about the fire caused by the promoters using air cannons to spray coloured powder into the audience which then ignited. I have to confess I've never been to one of these events and I has always assumed it was some form of fireproof/resistant/treated, non-toxic powder but never even thought to question what it was exactly. I am a little stunned to learn today that it is corn starch based with dyes and which of course is flammable. If it is a very fine, dry powder and mixed well with air, we all know how well it can burn. I've even made a few fireballs with corn starch and they work fairly well which doesn't bode well if you are stood inside a giant cloud of the stuff does it? 

Surely H&S are going to need to look at this for all the colour run type events in the UK? I just can't see how throwing tons of starch into the air is a good idea! Or am I being overly melodramatic about this. Or are the fire-retardants added to the powder over here? 

Please don't watch the video if you are easily shocked. It is graphic.

http://edition.cnn.c...park-explosion/

 

 

[Bob Twells]

Bloody hell that is terrifying. I've been to one of these events, and am well aware of how well certain seemingly harmless powders can burn, but it never even crossed my mind at the time. I would hope UK event companies are more switched on than this.

[dr thrust]

Yep corn starch, dangerous when mixed with air,
i remember a explosion in the news years ago a wall ,ect blown out of a factory.
Dust explosion.. In the birds custard factory, corn starch and air.....

[Bob Twells]

The Color Run UK Facebook page says their powder has been "tested for flammability", but gives no details as to the testing carried out (i.e. a big difference between a pile and an airborne cloud of the stuff). Their FAQ also states the powder is corn starch based, which gives cause for concern.

[cooperman435]

Worth considering too that you'd need a certain concentration of it to sustain or spread a flame, outdoors and in localised areas of release I think it's less likely to build up to that point?

[Arthur Brown]

I once sprayed a kilo of a cellulose powder over a flame in a safe place for a test. It burned fiercely in huge billowing flame.

[Sparky]

I also looked at the Colour Run site as my partner and her kids do it and I'm sorry but no one has really looked into it as far as I can see. Dust explosions are a well understood problem in industry and here we are creating perfect environments for them but for fun.

They are making the organisers of that incident sound like maniacs but reality that could have happened anywhere a dust cloud is formed, no one would know the risks unless they were trained and static can ignite them.

 

You simply cannot throw up huge clouds of dust like this and say it is non-flammable. Even the most mundane substances are more flammable than people imagine when it's ultra dry and a fine dust. 

[Arthur Brown]

Some substances burn, some simply don't and never will -think starch or a dry powder extinguisher.

[fruitfulsteve]

The dry paint they use for holy day celebrations in India is a bit like coloured talc. Never actually tried setting light to any but there are usually lots of fireworks being let off at the same time as people are throwing this paint at each other. Maybe they use some sort of inorganic powdered paint that just don't burn.

[bangkokpyro]

I've recently made coloured smoke shells from cornflour mixed with food colouring. These were 4 inch canister shells containing around 400 gms and burst with a 10 gm flash bag. The cornflour did not ignite just produced a cloud of colour.