This work analyses possible deficiencies in conventional teaching when the concepts of substance and chemical change are introduced. These deficiencies may be caused, in our opinion, by not taking into account the History and Epistemology of Chemistry. When teaching chemical reactions, the relationship between the two levels of representation – macroscopic, introduced with the empiricist model during the 16th and 18th centuries and microscopic from the 19th-century classical atomic model – are often forgotten. This study analyses chemistry teachers’ opinions on these subjects and the way they are presented in textbooks. The results obtained confirm the existence of significant conceptual and epistemological teaching deficiencies, such as failing to introduce the macro and microscopic definitions of substance and the lack of references to both levels in the presentation of chemical reactions