The present work analyzes the influence of seepage and desorption processes on the initial conditions of coal and gas mini-outbursts. A series of laboratory experiments incorporating coal briquettes and three different gases, namely carbon dioxide, methane or nitrogen were carried out. Experiments relied on mini-outburst inducing. Space and time pressure distributions along the briquettes were recorded. A comparative analysis of the results revealed that the observed differences in mini-outbursts initial conditions cannot be explained by means of a simple coal or gas property such as sorption capacity, desorption rate, seepage rate, or viscosity of gas. On the contrary, the efficiency of accumulated gas releasing processes - desorption and diffusion inside of the coal grains and seepage through the briquette coupled processes - seems to explain the observed variations. (C) 2013 Elsevier Ltd. All rights reserved.