This article discusses issues of risk in the production of biogas from primarily farm wastes. Biogas production is becoming widespread in Europe, and the number of accidents in these plants, both large-scale and small, is increasing. Recent accident experience is summarized here. Compared with the petrochemical industry, damage levels in biogas production are low, but nonetheless worthy of increased application of modern safety and risk methodology. (c) 2015 American Institute of Chemical Engineers Process Saf Prog 34: 172-178, 2015