Smoke and CO Evolution from Cotton and Flame Retarded Cotton. Part 1: Behaviour of Single Layer Fabrics under LOI Conditions

Abstract
The limiting oxygen indices of two different area densities of untreated and phosphorus-containing flame retardant cotton fabrics (Proban CC, Amgard TR, Amgard CD) have been determined at 20 and 100°C. Simultaneous smoke and CO evolutions from all the fabrics have been determined at respective LOI and (LOI + 0.010) oxygen concentration conditions at 20 and 100°C. At 20 ° C, flame retardants present greatly increased smoke generation whilst little if any change in CO generation (except for the bromine-containing Amgard CD) occurred. Whilst increase in temperature to 100°C reduced fabric LOI and increased apparent and specific smoke optical densities its effect on CO generation was not straightforward. Lightweight, bromine-free flame retarded fabrics showed increased CO formation whilst for the heavier fabrics, increased area density and/or presence of bromine stabilised or reduced CO evolution.