In previous chapters it has been argued that the implementation process can be examined through an analysis of the frameworks, structures and styles of regulation. It has also been argued that the impact of regulation can be assessed through an analysis of the influence that regulation has on the technological, organizational and strategic behaviour of the firm. This chapter draws on the categories and variables established in the preceding discussion to analyse the implementation and impact of mandatory and voluntary environmental regulation in the UK. The discussion presents the results of fieldwork conducted in the UK during 1995 and 1996. This work consisted largely of semi-structured interviews with policy-makers, regulators and representatives of industrial installations associated with the mandatory and voluntary regulations in question.