This article provides a comprehensive empirical analysis of the composition, development and use of the List of World Heritage in Danger (IDL) under the 1972 Convention concerning the Protection of the World Cultural and Natural Heritage. The statutory records of this Convention have been coded in order to generate an overview of the development and use of the IDL between 1978 and 2017. The quantitative data was further developed by reference to World Heritage and transnational law literature. A key finding of this article is that the IDL serves a dual purpose in regulation: firstly, as a 'fire alarm' to alert the international community of imminent dangers at World Heritage sites; secondly, as a non-compliance procedure used for 'naming and shaming' states that breach the rules. The findings in this article have relevance for heritage scholars and policy makers concerned with the governance of World Heritage as well as those with a broader interest in non-compliance procedures under transnational environmental law.