One of the best articles on celluloid is on the Oregon Knife Collectors Assoc (OKCA) website. This excellent article is written by Dennis Ellingston, (ibdennis) and appeared in the Knife World in 1999.
There really does not seem to be any “safe” or “good” celluloid. Celluloid is what it is; a close relative of nitrocellulose and you can’t change the nature of the stuff and make it safe. There are other colorful materials that have been substituted for celluloid, yet none seem to have the beauty, versatility and appeal of celluloid. But within the molecular structure of celluloid there seems to be a ticking time bomb and no one knows when it is set to go off.
There has been celluloid imported for use on knives in recent years and there have been knives imported that have celluloid handles, but even some of the newer knives have self-destructed. Read through AAPK and you will see some of these mentioned. I believe Bulldog knives had a problem with this, IIRC.
Here are pics of a Case XX that I repaired for a customer. The celluloid had destroyed the liners causing them to crack, rendering them useless. The gas given off from the decomposing celluloid had even pitted the nickel silver bolsters. I had to find a used frame with worn down blades to repair the knife. Essentially, I put new handles on a used frame and moved his blades into the new frame.
This is the knife before I started:
After removing the handle and scraping off some of the crud, here is what it looked like:
This is the pile side of the knife:
This is the pile side after the handle was removed. Note the crack to the left of the rocker pin.
The crack extended more than half way from the bottom of the liner toward the top of the liner.
This knife was so badly damaged that the knife essentially fell apart in my hands while taking the blades out.
I know one collector who had some knives in an enclosed brief case. He had not opened the case for a month or so. When he opened it, one of the celluloid knives had begun to off-gas and had damaged other knives in his collection. Though all of the knives were not totally destroyed, most were damaged. Since some were high dollar knives, he figured he lost about $1500 in value of the knives in this brief case. Needless to say, he is no longer a fan of celluloid.
I do have some celluloid in my collection, but I try to keep them in the open on a shelf so that air can circulate around the knife. This prevents the gas from being held around the knife, thus accelerating the process and causing more damage.
Is a knife repairman, one of the most frequent repairs I do is to replace celluloid handles for customers.
Dale