What is the Difference Between Flame Retardant and Flame Proof Fabrics?

Flame retardant does NOT mean that a fabric will not burn.Just about any flame retardant fabric will burn to some extent,depending on the degree of heat.What distinguishes an FR fabric from an non-FR fabric is the degree to which each will burn.

Flame Retardant fabric will experience much less burning - when fire is introduced to the fabric,the flame retardant properties of the fabric will cause the flame spread to be slowed considerably (sometimes to almost nothing) and the flame will self-extinguish once the initial flame source is removed.With an non-FR fabric,there is nothing to retard the flame,and therefore the flame will spread rapidly through the fabric and will continue to spread,even after the initial flame source is removed.

Flame proof fabric is considered non-combustible and will not burn due to its extremely high heat resistance. One example is Glass Cloth.