Grain dust is a complex mixture of organic and inorganic materials, mainly comprising the cellulose-based seed coating and the carbohydrate. In this review we focus on exposure to inhalable and respirable dust exposures, plus airborne endotoxin and mycotoxin concentrations. The main focus of this review has been to attempt to identify those tasks that may produce significant exposure to any of the above aerosol components, to estimate the approximate level of exposure in these tasks, and comment on the significance of exposure controls and the use of respiratory protection.