What it is
Nitrocellulose, also called Cellulose Nitrate, is a derivative of cellulose, which is then treated with water or alcohol and sold as a wet powder.
What it does
Nitrocellulose is mostly used in nail polish due to its film-forming properties: when it dries, it forms a tough, shiny and durable protective layer on the nails, but still allows them to breathe.
Nitrocellulose is generally considered to be safe.