Burstproofness of chemical apparatus. The first part of the paper deals with the safety requirements that have to be met by pressure vessels, the interaction of material behaviour and structural form, and the design principles in industrial codes. An important pre‐requisite for the avoidance of brittle fractures is material toughness also at those parts of the pressure vessels where increases in stress due to the shape of the vessels cannot be avoided. As a result of the development of new materials, the Dechema technical committee „Materials and design in the construction of chemical apparatus”︁ constituted the working party “Strength and toughness” in 1962 and assigned to it the task of carrying out bursting tests on model pressure vessels similar in size and shape to those used in practice, the purpose being to tudy the influence of material toughness and vessel shape on burstproofness. This study, which was completed early in 1979, is reported in the second part of this article.