For the land-use planning system, which often deals with tangible, physical matters, situations where a large-scale hazard (or potential for harm) may have only a very small risk (or probability) of being realised, can be especially problematical. One widespread example relates to the storage or use of hazardous substances, where, in the event of a major accident and release of toxic, explosive or flammable materials, local people and the nearby environment may be seriously affected. The UK planning system has been taking account of such hazardous installations for the last two decades, with European legislation further reinforcing this position under a forthcoming revision of the EU 'Seveso' Directive. The purpose of this paper is to evaluate the treatment of such hazard issues within local develpment plans. A survey of local planning authorities and an analysis of plan policy content, is used to reveal the extent to which development plans are addressing the land-use implications of major accident hazards, the approaches and types of policies that are being employed, and the implications for both land-use policy and developing spatial patterns of major hazard in the UK. Before discussing the results of the survey and policy analysis, the context within which major accident hazards are now incorporated within land-use planning practice is first reviewed.