Flammable film

[Assasin]

Anyone know if the film used in the 30s to 40s was nitrate or was it flamable to explain why so many films are lost maybe?

[faginsgirl]

I dunno about being flammable but I think a lot of them would have probably thrown away, thats what happened to a lot of lost film, thrown in skips. Sacralidge!



xx

[darrenburnfan]

All cinema films made up to around 1951 or 52 were on nitrate stock, which was highly inflammable and also deteriorated and started to disintegate with age. In the early 1950's, safety film was introduced, that would melt under heat, but wouldn't burn. I heard that many old films from the silent period and well into the 1940's are lost to us because the films have quite literally disintegrated. Although big, important productions such as The Four Feathers (1939) and The Thief of Bagdad (1940) have been restored for posterity by the BFI.

[orpheum]

This applies only to 35mm not 16mm which so far as i am aware was always issued on safety film as it was for home as well as theatrical use.

The problem with Nitrate is that it is unstable.It is self combustable and there is no way of extinguishing the flames.also as posted above eventually it turns to dust.So unfortunately a great deal of our film heritage has been lost for ever.

[LukeAFB]

I seem to recall a doumentary about Denham Studios about 15 years ago, where a long forgotten storage shed was entered for the first time in living memory. It contained many of the masters of 'classic' Denham produced films, all of which were on nitrate stock. When the cans were opened, 99% of these irreplaceable films were, as has already been mentioned, simply dust or jellified blobs. A great shame!

[Lord Brett]

I have also read (though cannot vouch for the accuracy of this statement) that a large percentage of British silent films were melted down to reclaim the silver from the silver-nitrate film stock.

[Windyridge]

I recently toured the Archives at the BFI near Aylesbury, which was fascinating. We were shown where the film is stored, at what temperature and told the history of both nitrate and safety film. I heard stories about dreadful fires in projection rooms (once nitrate film is on fire, it's impossible to put out) and about the loss of many lives and beautiful art deco cinemas this way.



We were also shown technicians in the process of restoring film or replacing frames with newer versions. To some extent the BFI relies on the public finding and donating prints and film has turned up everywhere from attics to milk churns!

[christoph404]

If you want to know more about film preservation and nitrate film stock I would recommend reading "This Film is Dangerous: A Celebration of Nitrate Stock" edited by Peter Smither and published the FIAF ( Federation Internationale des Archives du Film) Its a fairly entertaining read and consists of essays and articles from various sources including , technicians historians and filmmakers and the book is supported by leading film preservationist Martin Scorsese.

[penfold]

All of the above is true....Nitrate film, improperly stored, goes through various stages of decomposition, shrinkage, flaking emulsion, turning to powder and capable then of spontaneous combustion. In its non-decomposed state, it is highly flammable, and because burning nitrate film produces oxygen as a by-product, a nitrate fire is impossible to put out, you can only isolate it. It will literally burn underwater.

However, with the exception of a few studio vault fires in the thirties, most of the films that have been lost are due to their being recycled for their silver and plastic contents.....from the full adoption of sound 1930 until the beginning of the first film archives in the late thirties - the BFI, Cinematheque Francaise, MoMA in the US - it was open season on Silents, and these films had no commercial value other than as scrap. Many of the films that did survive this period did so as the personal collections of the films' directors, which is why DW Griffiths' work survives nearly intact; he donated his colection to MoMA in the late 30's. Otherwise, the films that lay forgotten in back rooms were the luckier ones. The thing to remember is, if properly stored - or kept in stable, cool environments, sometimes more through luck than judgement - nitrate films can survive beautifully well; 100 + year old discoveries are still being made; the Mitchell and Kenyon collection (870 short films from an Edwardian company in Sheffield) The very first films shot in Britain in 1895/6, from a family of Fairground showmen, and the Corrick Collection, the repertoire of an Edwardian-era Australian travelling picture show preserved by the projectionists family in Tasmania....

[CaptainWaggett]

The flammability of nitrate film is, of course, a key plot point in Sabotage - it wasn't allowed to be carried on public transport (though unfortunately an exception is made )

[Steve Crook]

"there is no way of extinguishing the flames"

"once nitrate film is on fire, it's impossible to put out"



It's interesting how people think that nitrate film can break some of the fundamental rules of physics



If those statements were true then the fires would still be burning









The fire triangle is a simple model that shows what is necessary for things to burn. Take away any one element and the fire will go out.



There's even a piece in the Wikipedia article about nitrocellulose film saying "The US Navy shot a training film for projectionists that included footage of a controlled ignition of a reel of nitrate film, which continued to burn even when fully submerged in water." But there's no such training film.



There is a training film made by the Royal Navy, called "This Film is Dangerous". But that shows that although it's difficult to put out, it's not impossible. And there's no scene of it burning underwater - well, not for long



But such urban myths are hard to deny, they do sound good so people keep repeating them



Steve

[penfold]

I know all about that, Steve, the flaw in your reasoning is that, of course, putting a fire out is not the same as letting it burn out.... a nitrate fire will of course stop burning once all the nitrate has been burnt.....the fuel, in your diagram....not the oxygen, which as I said, burning nitrate film produces.....therefore, isolation is the only way to handle it. Isolating a burning reel underwater is a fine way to do it, but don't think that the water has put it out....the reel of nitrate (your fuel) has just run out.

[orpheum]

It is instructive to go into old projection boxes.The fire precautions are still apparent.They had to have their own separate fire exits.The portholes have steel shutters which can be brought down to prevent the fire spreading to the auditorium.Old projectors have cutters so that the projectionist can cut the film off if it burns.At all times a projectionist had to be by a running projector.

I was informed of the problem of extinguishing nitrate fires by someone who worked in a film archive so i do doubt that this is a myth..

[Steve Crook]

name='penfold']I know all about that, Steve, the flaw in your reasoning is that, of course, putting a fire out is not the same as letting it burn out.... a nitrate fire will of course stop burning once all the nitrate has been burnt.....the fuel, in your diagram....not the oxygen, which as I said, burning nitrate film produces.....therefore, isolation is the only way to handle it. Isolating a burning reel underwater is a fine way to do it, but don't think that the water has put it out....the reel of nitrate (your fuel) has just run out.

But putting it underwater also removes the heat from the triangle. I would expect it to continue to bubble and burn for a little while, but not for long



Steve

[christoph404]

I failed my Physics "O" level but things do burn underwater, magnesium flares for example and Im imagining the oxygen is extracetd from the water mollecules (H2O) to fuel that flame...........I think! Would a can of Nitrate film burn underwater? It might do, but I guess the point Steve is making is that there is a lot of folklore attached to the combustible qualities of nitrate film which I would tend to agree.

[Steve Crook]

name='christoph404']I failed my Physics "O" level but things do burn underwater, magnesium flares for example and Im imagining the oxygen is extracetd from the water mollecules (H2O) to fuel that flame...........I think! Would a can of Nitrate film burn underwater? It might do, but I guess the point Steve is making is that there is a lot of folklore attached to the combustible qualities of nitrate film which I would tend to agree.

Yes, but nitrate film doesn't burn with the white hot intensity needed to separate the oxygen from the hydrogen in the water. There is some oxygen in the nitrocellulose (C6H7(NO2)3O5) - but it was mainly the cooling effect of the water that I was thinking of



Steve

[christoph404]

name='Steve Crook']Yes, but nitrate film doesn't burn with the white hot intensity needed to separate the oxygen from the hydrogen in the water. There is some oxygen in the nitrocellulose (C6H7(NO2)3O5) - but it was mainly the cooling effect of the water that I was thinking of



Steve

Okay Professor, I believe you....chemical symbols make my eyes glaze over, possibly why I failed my Physics exam

[Steve Crook]

name='christoph404'] Okay Professor, I believe you....chemical symbols make my eyes glaze over, possibly why I failed my Physics exam

We didn't have many chemical symbols in our physics exams. We had a few in our chemistry exams though



Steve

[christoph404]

name='Steve Crook']We didn't have many chemical symbols in our physics exams. We had a few in our chemistry exams though



Steve

I was hopeless at chemistry as well science wasn't my forte which in my youth meant a rejection to get into photography college, a godsend really as it meant going to art school instead where I learned a lot more about photography without the tedium of having to know the physics and chemistry of it all! I can develop film and make prints etc, just don't ask me anything too involved about technical properties of stuff!!

[penfold]

From the Health and Safety Executive leaflet on Nitrate film.....



unlike many other flammable materials, nitro-cellulose does

not need the oxygen in the air to keep burning and once it is

burning it is extremely difficult to put out. Immersing burning

film in water may not extinguish the fire and it could actually

increase the amount of smoke produced.



Nitrate also burns with a furnace-like heat and intensity.....but which also will catch fire at 38 C....which is why water will not sufficiently cool it to put the fire out.