FR refers to a fabric that has been treated to be flame retardant per established fire code standards and ratings. Flame retardant fabrics are created by applying flame retardant chemicals. Flame retardant chemicals are dissolved in water and then applied to the fabric through dipping or spraying. When the fabric becomes dry from this process of application, flame retardant chemicals adhere to the fabric fibers which make the fabric Flame Retardant on an impermanent basis. Flame retardant chemicals will be removed when exposed to water, making machine washing or dry-cleaning problematic. Humidity and airborne dust and oils can also diminish the endurance and effectiveness of the flame retardant chemical.