This chapter reviews central government policy guidance and outlines planning roles, and the types of environmental risk addressed and methods of intervention available in each case. It explores industrial major accident hazards and examines contaminated land risks more closely, in each case reviewing the development of relevant planning policy. The chapter identifies a number of complexities and constraints which have limited the effectiveness of planning action. It considers the potential for planning control of risk, and the position of planning within the modernized structures of environmental risk management emerging in the late 1990s. Whilst planning practice is on a much firmer footing, research has identified a range of difficulties. A fundamental constraint on land use planning is its limited ability to change current patterns of land use. The land contamination found across the UK has been created by pollution and waste disposal often extending back to the 19th century.