[Borek]

http://www.ohio.com/mld/ohio/13697803.htm

Mitch: if you think it should be posted in some other forum, please move.

[mike]

I wonder what the experiment was?

"..an experiment using methanol.."??

What about fume cupboards, labcoats, and no naked flames? The same safety procedures should really be followed in school as everywhere else, closed shoes, long sleeves/trousers, safety glasses, labcoats, gloves, fume cupboards (or at least good ventilation).

And how much methanol did they even have in the classroom?? to burn all of those students? surely there should be a limit to the volume of flammable solvent allowed out in the open.

Safety first, think of the worst that could happen and make sure you prepare for it.

What in the world was the teacher thinking??

[Borek]

http://images.ibsys.com/2006/0123/6375527.jpg

The classroom doesn't look like a place where there was huge fire.

[mike]

Were the students perhaps soaked in methanol from a spill or similar?

[pantone159]

This New York Times article
http://www.nytimes.com/aponline/national/AP-BRF-Lab-Fire.html

says that:

The flash fire occurred during a standard experiment to show how methanol, a clear, flammable liquid, changes color when heated, said Christopher Burner, dean of faculty.

[mike]

changes colour when heated

I have not heard of this before. This means they were deliberately heating methanol, that is crazy!

[Mitch]

From clear to fire. I suppose.

[Borek]

http://www.ohio.com/mld/ohio/news/13706380.htm

[pantone159]

That last article said they were using metal salts dissolved in MeOH for flame tests.  That makes more sense than just heating MeOH, as the NYT article seemed to imply.

[jdurg]

That last article said they were using metal salts dissolved in MeOH for flame tests.  That makes more sense than just heating MeOH, as the NYT article seemed to imply.

Makes perfect sense as Methanol burns virtually invisibly which would make the color of the metal salt easier to see.  (It's actually a VERY pale blue color, but it's damned near impossible to see.  That's what also makes Methanol fires VERY difficult to deal with as you can't really tell exactly where the fire is).  Ethanol doesn't have as good an oxygen-carbon ratio so it burns a bit dirtier.

[mike]

Ahh I see, this makes much more sense, this is a classic demonstration of the flame test.

Sounds like an unlucky accident. Although I do this demo at work and I always use a hood, keep the actual bottle of methanol closed and no where near the demo, and have sand and other "covers" ready to put over the fire (+ the usual fire extunguishers, fire blankets, shower etc etc)

[hmx9123]

I could almost guarantee you that the demo was the classic one with the metal salts dissolved in the MeOH in a petri dish, then lit on fire.  The same accident occured here in California a number of years ago, badly burning several students and blinding one.  The teacher, instead of covering the methanol-filled dishes, let the fumes build up in the poorly-vented classroom, and when he went to light the dishes, the vapors from the MeOH were within the LEL and UEL, thus causing a fuel-air explosion.  Glass everywhere, big fireball, students burned, a real mess.  I have a xerox of the newspaper article somewhere.  Seem to remember a HS in Bakersfield, but could be wrong about that.

[Donaldson Tan]

WTF.. that is some scary s-h-i-t!!!

[DrCMS]

If it was being done the way you describe it I would say it was not an unlucky accident but an obvious failure route just waiting to happen.  

In my job if i were to suggest taking a flammable solvent pouring it into open containers on an open bench and igniting it i'd get sacked.

To see the flame colours why not dissolve the metal salts in demin water and coat them on the end of a platinum wire and put them in the tip of a blue flame.  Thats how we did it at school.
You can see the colour without the dangers of the solvent.

[mike]

In my job if i were to suggest taking a flammable solvent pouring it into open containers on an open bench and igniting it i'd get sacked.

Is your job a firefighter?

I have done this demo before with no worries