Concerns about nitrate-based vintage negatives

[drcy]

Celluloid, a vintage plastic used to make film, billiard balls, toys, fountain pens, pins, mirror and brush handles, etc. is flammable. That's one reason why they discontinued making it. However, I don't think that means it's a major hazard to humans life and limb. Your celluloid pins aren't going to explode in your closet, and, of course, a stack of Baseball Magazines is also flamable. But they should be kept under good conditions as celluloid often can deteriorate/age with time. Degraded cellulid pins and such get cracks, alegator skin and discolorization (toning).

Old movie films were famous for melting and catching on fire in the projectors, but that was under the heat of the projectors while being shown. They wouldn't suddenly combust on their own sitting in a drawer.

Celluloid was first use to make fake ivory billiard balls and was commonly used to make other fake ivory items. Allen & Ginter pins are celluloid. And many of these still exist.

Anne Frank wrote her diaries with celluloid pens, and her favorite one burnt up in a small, minor fire in her family's hideout. She wrote about it in her diary. She knew the pen was celluloid and was well aware celluloid pens were flammable. Apparently, it was common knowledge back then. The pen and a blank diary book were given to her for her 13th birthday and that's when she started writing her famous diary.

The can of turpentine in your closet is more dangerous than old film.

[Runscott]

Reminded me of this scene from 'Cinema Paradiso' where the film catches fire:

Cinema Paradiso - Fire Scene

[Chris-Counts]

A few years back, I purchased about a half dozen baseball negatives from the late 1930s. A couple months later, they morphed into a weird science experiment. They crackled and bubbled and curled. They were completely ruined, so I disposed of them for fear they might ignite ...

[steve B]

Originally Posted by drcy

Celluloid, a vintage plastic used to make film, billiard balls, toys, fountain pens, pins, mirror and brush handles, etc. is flammable. That's one reason why they discontinued making it. However, I don't think that means it's a major hazard to humans life and limb. Your celluloid pins aren't going to explode in your closet, and, of course, a stack of Baseball Magazines is also flamable. But they should be kept under good conditions as celluloid often can deteriorate/age with time. Degraded cellulid pins and such get cracks, alegator skin and discolorization (toning).

Old movie films were famous for melting and catching on fire in the projectors, but that was under the heat of the projectors while being shown. They wouldn't suddenly combust on their own sitting in a drawer.

Celluloid was first use to make fake ivory billiard balls and was commonly used to make other fake ivory items. Allen & Ginter pins are celluloid. And many of these still exist.

Anne Frank wrote her diaries with celluloid pens, and her favorite one burnt up in a small, minor fire in her family's hideout. She wrote about it in her diary. She knew the pen was celluloid and was well aware celluloid pens were flammable. Apparently, it was common knowledge back then. The pen and a blank diary book were given to her for her 13th birthday and that's when she started writing her famous diary.

The can of turpentine in your closet is more dangerous than old film.

Celluloid covers a number of plastics. The ones used for movie film and still negatives are different from the less flexible versions.
I own films on at least four film stocks, probably five. That includes nitrate movie film. I've also burned both nitrate two types of safety film.

Cellulose nitrate - Nitrate film, in movie film it was phased out in different years for different formats. 16mm introduced in 1923 was never on cellulose nitrate, 35mm was often on nitrate until 1948 when cellulose triacetate was introduced. Production stopped at Kodak in 1950, and it was discontinued in 1952.
It burns very aggressively, and is self oxidizing so it's hard to extinguish.
The byproduct released is nitric acid, and in non-vented containers will eventually self destruct. It can spontaneously combust, but I haven't heard of that happening with still film, although it was apparently a major problem with stored x rays.

Cellulose diacetate - from 1909, an early safety film. I had what I think was a 1920's film that was not marked as nitrate or safety. It may have been this. Odd degrading, brittle but hardly any shrinking. It burned, but slowly, sort of like a candle. (That was my test for whether it was nitrate, took a torn frame outside and lit it in a metal tray. Nitrate goes up very quickly, this stuff hardly at all.

Cellulose acetate propionate and cellulose aceteate butyrate - 1930's safety film, used for all 16mm, 8mm, and some 35mm before 1948. As it degrades one form gets a bit of a barfy smell. (can't think of a better way to describe it. ) The other just shrinks and gets brittle.

Celulose triacetate - the common modern filmstock. Introduced in 1948, and it came in nearly formats eventually. Degrades by releasing Acetic acid (vinegar) but it's very stable and will take a lot of abuse before it degrades. Badly degraded film smells like vinegar and eventually shrinks curls and becomes brittle. It can be burned, but burns poorly.

Polyester - Mylar/Estar a few other brand names. Essentially inert, it can burn, but it's not easy to light. It melts at around 490F, so if your mylar is melted or burning you've already had a problem for a while.

Of those, only Cellulose Nitrate is any hazard.
By some tests, it's not a particular hazard outside of severe conditions
http://motion.kodak.com/motion/Suppo...ge_nitrate.htm

The relevant bit - a badly decomposed 1000ft reel in a sealed container took 17 days at 106F to retain the heat of decomposition.

In small pieces of good condition fillm it's manageable, and less likely to ignite.
http://www.youtube.com/watch?v=7mZDt8vYMBw

But once it does, it's Trouble.
http://www.youtube.com/watch?v=AL9izOFrqbw

http://www.youtube.com/watch?v=g00nYOueqSI

Deteriorated and tightly packed.
http://www.youtube.com/watch?v=SccNL6mfX2Q

So still film is probably not much risk if it's properly stored. Archival envelopes, not densely packed, and kept cool and dry.

A few hundred stacked in a box in the attic? Not something I'd do.
I keep my nitrate films in the refrigerator. Eventually I'll get around to getting them to someplace that can preserve them and store them properly.

Steve B

[Darner]

Thanks for that information, Steve.

The point is that you have to know what you have and then take care of them. All these early film stocks break down so if they're to last, they have to be stored properly but the flammability of nitrate and the noxious byproducts of its decomposition requires more attention.

I only have a couple of negatives from the '30s and they're not nitrate but when I bought them I had no idea what kind of stock they were. You usually can't tell from an auction listing and as a newbie, I didn't know to look. I can see nitrate being problematic for sellers. How would you even ship them if you can't legally put them in the mail?