What You Need to Know About Celluloid

Is It Really Flammable and What Is Celluloid Disease?

Celluloid Hair Comb Dyed to Look Like Tortoise Shell
Celluloid Hair Comb Dyed to Look Like Tortoise Shell with Rhinestone Embellishment, Ca. 1880s. Photo by Jay B. Siegel for Chic Antiques by Pamela Wiggins

Celluloid is actually a trade name, like Band-Aid or Kleenex, but the term has been generically used for many years to reference a type of plastic material invented in the mid 1800s and used to make a variety of objects until around 1940. It is actually a product of cellulose dinitrate blended with pigments, fillers, camphor, and alcohol to make a unique synthetic material categorized as a plastic.

What Does Celluloid Look Like?

Most people recognize the pale yellow pieces with graining meant to simulate ivory as celluloid these days. In fact, celluloid was often referred to as “French Ivory” in its heyday to give it a little more snob appeal and is sometimes marked as such, although the composition has nothing at all to do with genuine ivory harvested from animal tusks. Another similar term, Ivory Pyralin, is sometimes found stamped on these pieces as well.

Celluloid took many forms and colors during the time it was being used. It was inexpensive, easy to work with and durable when new (although it can deteriorate over time, as noted below). If you look around you can find knife handles, holiday decorations, razors, hair ornaments, dresser sets and even jewelry made up of celluloid, and many of these are still in good condition today.

While some of these items, especially dresser sets, can be found in the common pale yellow coloring, there are many other ways this plastic was colored and decorated.

Take celluloid jewelry as an example.

Some celluloid bangle bracelets decorated with row upon row of colorful rhinestones can be worth several hundred dollars apiece to the right person. This rivals prices being paid for jewelry made of another popular vintage plastic, Bakelite, also known as Catalin.

In comparison, celluloid is much lighter in weight and density than Catalin. 

Is Celluloid Dangerous?

Some collectors don’t realize is that celluloid is an extremely flammable substance, especially since seemingly harmless items like dolls and toys were made with it, and it should be kept away from heat sources. In fact, an article on the Oregon Knife Club’s website attributes this detrimental characteristic of celluloid to be the reason it wasn’t used much after 1940. It is also important not to store celluloid objects in an area prone to extreme heat such as an attic to avoid combustion.

Never use the hot pin test to verify that an item is celluloid. In fact, avoid this test entirely. It's not only dangerous when it comes to highly flammable celluloid, it can damage other types of plastics that have collectible value. If you want to test a piece you suspect to be celluloid, put it under hot running tap water. Celluloid omits the scent of camphor when heated in this way. Avoid getting old mirrors and jewelry with stones wet, however.

If the foil on the backs of these items has already started to deteriorate, moisture can make matters worse. 

Celluloid products have also been reported to emit fumes that can damage metal, specifically that used in jewelry and knife blades, so it’s not a good idea to store your vintage treasures made of celluloid in an airtight container or sealed in a plastic bag, especially when they're in proximity to other items.

All in all, however, celluloid antiques and collectibles are not dangerous as long as they are stored properly and kept away from open flames or extreme heat sources.

Why Do Some Pieces of Celluloid Deteriorate?

While celluloid was initially durable as a utility product, one downside to collecting this plastic is that some pieces don’t seem to hold up well over time and can chip, crack and crumble. Collectors refer to this as celluloid disease or celluloid rot. And while a definitive cause for this isn’t known, they’ve also discovered that it can transfer from one piece to another.

The Oregon Knife Club’s website also notes that clear or light colored celluloid items appear to be more prone to this phenomenon. Why? It is supposed that agents supplying the color to darker celluloid batches act as binding agents making the substance more chemically stable and thus thwarting, or at least slowing down, the deterioration process.

If you have a collection of celluloid items, whether that translates into jewelry, knives, or barber shop collectibles like razors, be sure to examine them from time to time to make sure that none are brittle or showing signs of cracking or flaking. If they are, it’s time to tell them goodbye for the sake of the rest of your collection.

Pieces in good condition should be stored where they can breath. Also take care to keep them from touching to avoid transferring celluloid rot from piece to piece should that unfortunately crop up among a collection.