Abstract Laser flash photolysis combined with competition kinetics with SCN− as the reference substance has been used to determine the rate constants of OH radicals with three fluorinated and three chlorinated ethanols in water as a function of temperature. The following Arrhenius expressions have been obtained for the reactions of OH radicals with (1) 2-fluoroethanol, k 1 (T)=(5.7±0.8)× 10 11 exp ((− 2047±1202)/T) M− 1 s− 1,(2) 2, 2- ...