Fire extinguisher in the early 60s and Purple-K being developed by the US Navy in the late 1960s. Manually applied dry agents such as graphite for class D (metal) fires had existed since WWII, but it wasn't until 1949 that Ansul introduced a pressurized extinguisher using an external CO2 cartridge to discharge the agent. Met-L-X (sodium chloride) was the first extinguisher developed in the US, with graphite, copper, and several other types being developed later. In the 1970s, Halon 1211 came over to the United States from Europe where it had been used since the late 40s or early 50s. Halon 1301
Fire extinguisher made by Metalcraft and Graviner which eliminated the moisture contamination problem. TMB/Boralon was abandoned in favor of more versatile agents, though it is still mentioned in most US firefighting literature. Buffalo marketed a 2.5-gallon and 1-quart extinguisher using M-X liquid discharged through a low-velocity shower head type nozzle but it was met with limited success, as it was going up against Ansul's Met-L-X, which could be used on more types of metals and was non-combustible. M-X had the advantage of being easy to recharge and non-corrosive since it was oil-based, but production did not last long due to its limited