Context: Safety-critical systems (SCS) are mainly controlled by software. Accordingly, the development of these systems must be carefully planned since inadequate or misunderstood requirements have been recognized as the major cause of a significant proportion of accidents and safety-related catastrophes. Objective: We investigate the integration and requirements communication in the requirements engineering (RE) process among different parties when developing SCS. Method: We used a Systematic Mapping Study as the basis for our work. Results: We analyze the challenges and needs involved, application context, research type, evaluation methods, type of contribution, domain, requirements activity as well as languages and tools used to specify safety requirements. Furthermore, we also analyze stakeholders involved, communication format, and for what safety standards have the approaches been proposed. Conclusions: We believe the results of such a study will benefit both researchers and practitioners. This information contributes to setting up possible collaborative networks and as a reference when developing new research projects. © 2019 Anais do WER 2019 - Workshop em Engenharia de Requisitos. All rights reserved.