Treatment for improving flame retardancy of wool and minimizing toxic gas evolution in burning

A treatment involving formaldehyde, a reducing agent, and a boron‐containing compound of a wool shag carpet imparted to it a flame‐retardancy effect that was effective after the seventh but not the eighth shampoo. This treatment also decreased the concentration of carbon monoxide and hydrocyanic acid generated in the products of combustion by at least a factor of 2. Analogous treatment of a wool flannel fabric produced a 15–22% sample area shrinkage and imparted a flame‐retardancy effect that was still effective after a 2‐hr cold water rinse.