This chapter adopts a historical perspective on the development of criminalization of health and safety law. In so doing, it emphasizes the divergence in perspective between criminal lawyers and labour lawyers on fundamental matters of value. Criminal lawyers have tended to focus on the development of criminalization-limiting principles as an exercise in normative theory, whereas labour lawyers have tended to focus on instrumental outcomes in terms of whether health and safety outcomes are improved. If criminal law works in that instrumental sense, then so much the better, and that supersedes niceties about the justifiability of criminalization. This chapter identifies the central importance of criminalization as a tool of deregulation in the modern era, following the removal of a civil right to seek compensation for breach of statutory duties under the health and safety legislation. By channelling enforcement exclusively through the criminal law, the individual worker is thereby disempowered in their standing to control the legal process and its outcomes.