Oil droplets from an emulsion were filtered using a slotted pore membrane with a 4 mu m slot width and 400 mu m slot length. Droplets up to 15 mu m in diameter were filtered at various flux rates (200-12001m(-2) h(-1)) using oscillatory membrane microfiltration. Surface shear rates at the membrane of various intensities (0, 1200, 3200 and 8100 s(-1)) were applied and the effect on permeate flux rate and trans-membrane pressure were investigated. Near constant filtration flux was obtained for all the tests. Without shear the trans-membrane pressure increased quickly, but at the highest shear rate (8100 s(-1)) nearly constant trans-membrane pressure and flux rate were observed and may be described as sustainable, or weak form of critical flux. A filtration membrane blocking model was used to investigate the filtration and identify when sustainable, or critical, flux was achieved. (C) 2011 Elsevier B.V. All rights reserved.