This report reviews the incidence of acute respiratory disorders in workers involved in production processes related to primary aluminium smelting, focusing on occupational asthma. Workplace exposure data quantifying contaminants capable of inducing respiratory disorders are presented. Possible sources of contamination include hydrogen fluoride, sulphur dioxide and fine dust fractions containing recycled impurities from emission control systems. Currently available control strategies based on these quantitative results are assessed. Critical comment is made on procedures currently in place to control workplace exposure and suggestions for improving engineering and work practices are summarised.