'Cellulose nitrate was used to make dice from the late 1860s until the mid twentieth century, and remains stable for decades. Nitric acid is released in a process called outgassing. The dice cleave, crumble, and then implode.'
Deception, Fate & Rotten Luck by Ricky Jay and Rosamond Purcell
There is also a none zero chance that if you rolled those dice hard enough that would explode. They had a real problem with celluloid billiard balls going bang which is not something you want to happen in a saloon in a place like, say, Tombstone Arizona in the 1880’s.