[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.