Inspecta-Shield FIRE RETARDANT is a Class A fire retardant for fibers, lumber, and wood materials. Pre-mixed, easy to apply, non-toxic, non-allergenic, colorless, odorless (when dried), durable, and UV stable. UL classified and approved by the CA State Fire Marshal. Works by slowing horizontal and vertical flame spread. Does not prevent charring, but treated items will not support ignition. Directions are included. Not recommended for outdoor use.