The rate of reaction of F atoms with a series of compounds, CH4, CH3F, CH2F2, CHF3, CHClF2, HCl, CBrF3, NH3, and PH3 has been determined relative to the chemiluminescent reaction[Formula: see text]by photometry. The fluorine atoms were produced in a flow system from the fluid mixing of molecular fluorine and nitric oxide diluted with argon.