Urban planning has played an increasing role in response to threats to health and safety, but this can create problematical conflicts with other planning priorities. The author examines how the UK planning system deals in practice with the safety implications of hazardous installations involving the storage and use of toxic, explosive, and flammable substances. The responses that have been made by local planning authorities to hazard-development conflicts in the vicinity of hazardous installations are evaluated. A distinction is made between those responses focused on development restraint through refusing permission for housing, community facilities, and other sensitive land uses, and those focused on the hazard source. It is argued that these last are becoming increasingly significant despite limitations in the statutory powers available. Through focusing on recent developments and drawing on a wide range of experience, the author adds to the existing research literature on planning and hazardous installations in which the evolution of policy and practice in this area has hitherto been rather sporadically examined. The implications of a recent policy focus on brownfield redevelopment, of new European regulations for hazardous sites, and of wider trends in relationships between industry, regulators, and communities at risk are considered.