The 2001 HSE regulations for the Norwegian petroleum sector include a paragraph requiring the promotion of a sound health, safety and environment (HSE) culture. This paper presents an examination of the function of the ‘culture’ concept in communications from the regulatory authorities to the industry. We discuss implications for organisational and interorganisational learning for safety. The regulatory authorities use ‘HSE culture’ in different ways depending on the document. No explicit definition of HSE culture is given in the regulations or the guidelines, whereas several diverging definitions are mentioned in an information pamphlet. In accident investigation reports, the HSE-culture concept has typically been used to characterise organisations with numerous violations of the HSE regulations or internal procedures. The concept has also been used to devise simplistic and possibly tautological explanations for frequent rule violations and to argue that numerous rule violations constituted a violation of the regulatory requirement to promote a sound HSE culture. The plasticity of the ‘HSE-culture’ concept proved to be a two-edged sword. By introducing the HSEculture concept in the framework regulation, the regulatory authorities explored an unconventional approach to HSE regulation. The ‘HSE-culture’ concept legitimated a very broad range of HSE approaches in regulated companies, some of which were unexpected by the regulatory authorities. In accident investigations, the use of the ‘HSE-culture’ concept in an explanatory capacity might lead to the premature closure of a search for the causes of an undesired behaviour or decision. The use of the term ‘poor HSE culture’ to explain or characterise extensive non-compliance in the investigation reports may have stimulated the regulated companies to prioritise HSE strategies and measures to enforce compliance.