Stain Rags can spontaneously Combust Causing a Fire.
DID YOU KNOW?
Did you know that old stain rags (and oily rags alike) if wadded up can ignite and cause a fire? It is more common then you think for people to stain a project then forget to properly dispose of the stain rags leaving their home or project in jeopardy of catching on fire. An average of 1,700 home fires per year are caused by spontaneous combustion or chemical reactions, and 900 home fires per year are due directly to oily rags that catch fire according to the National Fire Protection Association.
After using oily rags (brushes, painting & staining tools), completely submerge them into a metal container with a fitted lid filled with water. Follow local laws for disposal.