Local stability criteria for dust grains (left panel) and planetesimals (central panel) and growing dust grains (central and right panel) as a function of the radius in the disc, assuming various surface density slopes: p_dust = 0.5 (blue dashed line), p_dust = 1 (red full line), p_dust = 1.5 (green dash-dotted line). q_loc is defined as −dlog (T(r)) /dlog (r).