No other film in this series provoked more discussion and argument than this. Mostly from me. It’s a classic demo and was highly-requested in the nomination stage of Get Set Demonstrate, yet I argued against filming it.
For many years I made essentially all the science programmes that went out during the UK’s teatime ‘children’s television’ window, and there were only a few demonstrations I flat-out refused to show. This was one of them. You can show a safe method, you can treat the science with due respect… but with video you have precious little knowledge of your audience. You can’t tell when their attention has drifted away and they’ve maybe missed a crucial detail, you can’t be 100% certain of the message they take home, and most importantly you can’t guess what they might be tempted to try for themselves.
In person, the heat from the fireball is impressive: on video, it’s the size of your TV, or a YouTube window, or your phone. And it’s cold.
Film-makers can’t be responsible for the behaviour of their audience (discuss, 20 marks), but in this case the risk is very, very high. If 100,000 children saw the demo in our show, and 1 in 1,000 tried it themselves, and 1 in 100 set the curtains alight… that’s not something I ever wanted on my conscience. It’s not that the demo is too dangerous, it’s that it’s too easy. It’s trivial to perform it yourself in a kitchen, and the results can (and will) be catastrophic. So I never filmed the demo. Until now.
Others on the team eventually convinced me, using effectively the same argument applied backwards. The demo is straightforward to reproduce, and reproducing it is dangerous. Knowing that – understanding how and why oil fires are dangerous – might just save someone’s life, and for that reason alone, the team argued, this demo should be known and used in schools, and hence we should make this film.
I’m glad we did.
Three quick notes:
- In a UK school, follow the CLEAPSS guidance (Scotland: SSERC). As a teacher or technician you should consult CLEAPSS as a matter of routine before attempting hazardous activities, and where they issue standard guidance (as here): follow it. ScienceDemo.org doesn’t have access to the CLEAPSS archive so we can’t link directly to the resource, sorry, but you’ll find it easily enough.
- The formal government advice on how to react to a chip pan fire in the home is: get out, stay out, and call 999. It’s no longer considered appropriate to attempt the ‘damp tea-towel’ remedy yourself: the casualty rate is too high. We should have mentioned this in the film.
- In person, our fires were a little underwhelming, with the water often putting the flame out quickly. We’ve cut around that for the film, but speaking to other demonstrators subsequently it seems we were probably more assiduous than strictly necessary about turning the gas off the instant the flame caught. Give it a few more seconds and you’ll get a more satisfying fireball, we’re told. Do see Bob Worley’s comment below about one-upmanship, however!
This film was produced for the Get Set Demonstrate project. Click through for teaching notes, and take the pledge to perform a demonstration to your students on Demo Day, 20th March 2014.
That fire is not too “wimpy” in the context of a lab with a 3 metre high ceiling (and some ceilings are even lower). A demonstrator in a large University lecture theatre might create a larger one (some are on You Tube and badly done). Risk assessments are not just about the chemicals but also about the room you work in.
This is just how serous incidents occur with teachers trying to outdo each other. There have been examples of this setting of heat activated fire alarms (Yes done under the alarm, doh.)
CLEAPSS had to produce guidance on this because teachers were being burnt spraying in water with wash bottle or using far too much oil. We are not being killjoys but basically trying keep teachers out of trouble and not being seriously hurt. For those of you who subscribe to CLEAPSS, the information is in Guide L195 at present but I suspect will be made into a supplementary risk assessment in due course.
Bob
Thanks, Bob – I’ve edited the article to remove the ill-chosen word ‘wimpy,’ but also to better describe what happened during production. There have been lengthy discussions behind-the-scenes about this film because the raw footage really was quite unimpressive. To an extent that’s the limitations of cameras and web video rearing their heads, but there’s another problem here:
This is a very familiar demo, thanks to a thousand YouTube films. Many of those may be reckless, but they do set an expectation of what you’re going to see. In practice, following the guidance, several of our attempts could reasonably be described: ‘the fire spat a bit, then went out.’ If the purpose of the demonstration is to impress upon students the dangers of oil fires, that’s a failed demonstration.
One’s natural inclination is probably to use more oil – bzzzt! Nope, wrong. Don’t. But personally, I was left with the impression that this demonstration had been toned down beyond the point where it works theatrically. A safe demonstration isn’t always effective, which to my mind implies one shouldn’t perform it. I’ve taken some persuading that the chip pan fire demo doesn’t fall into this category.
What we’ve learned subsequently is that it is possible to extract a satisfying performance from the recommended 3ml oil. On that basis I’m again happy to promote the demo to teachers for their consideration.
Of course, this discussion is part of why we started this site. Delivering demonstrations is a careful balance between storytelling, emotional response, pedagogy, and not harming anyone.
This is an interesting demo regarding safety, I think it almost becomes more dangerous if the effect is too small, because the size of the effect on the video is verging on looking fun rather than scary.
Which could probably be more dangerous overall than slightly charring the ceiling.
Exactly, Dave. Several of our takes were in that “Woah! Cool!” category rather than “Woah! Scary!” (inevitably followed by nervous laughter borne of relief). It’s the latter you want for the message to have impact, otherwise you’re just showcasing something that’s readily repeatable, only with less care.
why not simply complete the demo by showing how you can put it out – the wet tea towel. (and you can explain the science of that too if you want). Then as well as knowing that pouring water is not the thing to do, you know what is. That might actually save a life.
Averil: See my second note in the main story. We don’t talk about putting out the fire because the advice has changed (apparently some time ago, but it was news to me too). The success rate with a damp tea towel is apparently rather low and the casualty rate rather high, so the government advice now is to get out, stay out, and call 999.
That sort of crisis-level fire safety really isn’t my area of expertise, and I’ll absolutely defer to the expert opinion.
As someone who has been faced with a burning oil fire in a kitchen and no easy options I can’t emphasise too much how much heat is put out. I was very lucky – facial hair scorched and some burns on my leg, arm and hand that don’t cause me any trouble. If I had seen the wet tea towel used effectively before I might have tried that, but I would bet that most of the moisture would have been evaporated away very quickly before even making contact. As for demonstration this – if it can be done safely for all the reasons discussed the audience is unlikely to forget it