The kinetics of the purely chemical production of nonequilibrium concentrations of Cl atoms from the ClO2/NO chain reaction is discussed. It is shown that this chemical system is suitable for producing Cl atoms to pump a cw HCl laser and that there are three modes of accomplishing the prepumping chemistry. A hybrid HCl/CO2laser was operated using this chemistry which gave 7 mW output power at 10.6 &mgr;m. A transverse flow HCl laser was operated having a multiline output power of 13 W and a chemical efficiency of 8%. The three modes of accomplishing the chemistry were demonstrated with a transverse flow HCl laser.