This note compares recent work on flame size and soot escape. The criteria found for soot escape by various workers arc in reasonable agreement, differing slightly due to different definitions of the end-point. However, the recent statement is incorrect, that the effect of O2concentrations on diffusion flame size disagrees with the theory of Roper. The temperature effect observed is in excellent agreement with this theory. The present work also suggests that buoyancy effects must be included when considering the effects of fuel flowrate on soot escape.