Modeling of induction thermal plasmas has been performed to investigate chemically non-equilibrium effect for dissociation and ionization. Computations were carried out for argon-oxygen plasmas under atmospheric pressure. The thermofluid and concentration fields were obtained by solving two-dimensional modeling. This formulation was presented using higher-order approximation of the Chapman-Enskog method for the estimation of transport properties. A deviation from the equilibrium model indicates that argon-oxygen induction plasmas should be treated as non-equilibrium for dissociation and ionization. The present modeling would give the guidance for the rational design of new material processing using thermal plasmas. (c) 2005 Elsevier Ltd. All rights reserved.