In 1959, a series of original investigations by NRL in the area of chemical flame extinction gave birth to the discovery of a new, dry chemical agent called potassium bicarbonate powder. Powdered bicarbonate of soda had been used as a flame-halting agent for many years, but its action had never been satisfactorily explained.
Working with other investigators, NRL conducted fire tests with many powdered substances that helped explain the chemical actions involved. Scientists concluded that simple substitution of the potassium ion for sodium extended the flame-quenching efficiencies of the chemical powders by a factor of two. American industry was called in at that point, and the new highly effective product, called Purple-K-Powder by its NRL discoverers, became used throughout the Navy and in U.S. municipal and industrial fire protection operations, and thereafter throughout the world. It is the only dry chemical agent recognized by the National Fire Protection Association for airport crash rescue firefighting.