Fire safety regulation is changing as adherence to prescriptive requirements is being replaced or complemented by an approach based on performance based design (PBD). However, this shift in regulatory practice raises important issues concerning the ability of regulators to provide competent oversight of fire safety engineering. This stems from the inevitable ‘expertise asymmetry’ that exists between regulators and those who are regulated, and means that regulators must rely on, and trust, data and analysis that is produced by industry. This dilemma could logically be resolved if fire safety engineering was accorded the status of a self-regulating profession whose competence and ethics were trusted by regulators. However, there are two main barriers to this: doubts about whether fire safety engineering is yet sufficiently mature as a profession; and concerns about whether the probabilistic nature of fire risks make fire safety engineering unsuitable for self-regulation.