A non-equilibrium modeling of argon-oxygen and argon-hydrogen induction thermal plasmas was performed without thermal and chemical equilibrium assumptions. Reaction rates of dissociation and recombination of diatomic gas and ionization were taken into account with two-temperature modeling. A substantial deviation from LTE exists near the torch wall in argon-oxygen induction plasmas under atmospheric pressure, while small deviation in argon-hydrogen plasmas results from the large collision frequency between electrons and hydrogen atoms. (c) 2006 Elsevier Ltd. All rights reserved.