The effect of laundering variables on the flame retardancy of cotton fabrics

Some durable flame retardant finishes for cotton fabrics can become ineffective if improper laundering procedures are used. For example, one flame resistant fabric will lose a significant amount of its flame resistance after 5, 10 or 20 soap launderings (yet show no reduction in phosphorus content) while another fabric treated with a different formulation will remain flame resistant. Synthetic detergents, rather than soap chips, and soft water have been recommended for some tetrakis (hydroxymethyl) phosphorium chloride‐based flame retardant fabrics to prevent a “lime soap” deposit which impairs performance. The effect of these laundering variables has been studied in relation to a variety of different types of durable flame resistant fabrics.