The creation of the International Labour Organisation was based on a consensus among nations that it was necessary to create a common law that would provide employees with a dignified life. The aim was to pacify the working class, which was demanding improvements in labour conditions. The study assessed the theoretical and practical mechanisms for consolidating the standards of the Conventions linked to the Organisation, ratified by Brazil, which deal with the right to a healthy working environment. To this end, a historical overview was made of the rules on occupational safety since the creation of the International Labour Organisation. It also presented and analysed the Conventions linked to the Organisation, ratified by Brazil, which deal with the fundamental right to a healthy working environment and the repercussions on the legal system. Finally, the problems that hinder the absorption of international treaties on occupational health and safety into the Brazilian legal system were identified. The work is aimed at academics and professionals in law and other areas of knowledge.