Relative rate coefficients (in cm(3) molecule (1) s (1)) for the gas-phase reactions of OH radicals and Cl atoms with diethyl sulfide (DES) and ethyl methyl sulfide (EMS) have been determined at 298 K and atmospheric pressure using long path in situ FTIR analysis: k(OH + DES) = (1.65 +/- 0.71) x 10(-11), k(Cl + DES) = (3.14 +/- 0.89) x 10(-10), k(OH + EMS) = (1.11 +/- 0.29) x 10(-11), k(Cl + EMS) = (3.06 perpendicular to 0.42) x 10(-10). The rate coefficients did not show any dependence on the oxygen partial pressure and are compared with previous determinations. Reactivity trends and atmospheric implications are discussed. (c) 2009 Elsevier B.V. All rights reserved.