We derive approximate relations for the propagation velocity and the maximal temperature rise of an "ideal" 1-D front in a pseudo-homogeneous packed bed reactor (PBR) model with a first order activated kinetics, accounting for a finite mass Peclet number (Pe(C)). These relations are compared with known approximations for Pe(C) -> infinity and are verified by direct numerical simulations showing a good agreement within a wide domain of parameters if Pe(C) > Pe(T), which typically applies for PBRs. (C) 2009 Elsevier B.V. All rights reserved.