Abstract: A system for delaying the ignition of, or for extinguishing, an oil well rig fire, by injecting an admixture of for example pressurized CO.sub.2 and mono-potassium phosphate into the flow of hydrocarbons from the drill pipe and casing, through a plurality of holds in the wall of a spool apparatus located in the "stack" above the "Hydril" and blow-out preventers and above the casing but preferably below the mud return line element. The spool apparatus is equipped with a plurality of one-way check valves for receiving a plurality of conduits or chicksaw lines for transporting the chemicals from storage tanks to the spool apparatus. The entire system can be manually activated by a spring-loaded mechanism at the control head. Additionally, the system can be used to inject, for example, ammonium hydroxide to neutralize highly toxic gases, known as "sour" gases, arising during a blow-out.