This book analyses the treatment of uncertainties within risk management and regulation for hazardous wastes, in five national case-studies. It is shown that, although institutional uncertainties vary between national political cultures, regulatory bureaucracies everywhere understate these more fundamental uncertainties (which are often structural conflicts, of different rationalities) and define them instead as marginal technical uncertainties or imprecision in risk-definitions. Close comparative analysis shows that technical regulatory standards depend upon their local institutional setting in systematic ways, so that conventional regulatory emphasis on technical precision or standardisation should be replaced by greater social negotiation, and educated public involvement and control. Readers will find the book valuable for its novel analytical approach especially in relation to public acceptance issues, and the argument for fresh practical approaches derived from this; in addition there is new information and analysis from the descriptive materials in case studies. Its main aim is to stimulate fresh thinking and approaches to an urgent problem.