The Practical Food Microbiology Series gives practical and accurate information about specific organisms of concern to public health. The information is designed for use by those in the food industry working in manufacturing, retailing and quality assurance, those in associated professional sectors e.g. public health, and students in each of these areas. Clostridium botulinum produces a toxin which causes the severe, often fatal illness, botulism. It is a potential hazard associated with a wide range of both ambient stable and chilled foods. Foodborne botulism still occurs all around the world. As new outbreaks are reported implicating yet more food types and food processes, so the food industry needs to regularly review processes and product characteristics to assure safety.