This report presents the results of a feasibility study for improving transparency and accessibility of the models implemented in the Monte Carlo Risk Assessment (MCRA) web platform for assessing the risk of combined exposure to multiple chemicals via multiple exposure routes. It provides an overview of the history and current use of the web platform and its scientific and regulatory context. The technical infrastructure of the current MCRA web platform and the modular design of the various models of MCRA are described. Based on selected user stories, user requirements are established, and suggestions are made for possible designs of an open source collection of MCRA models. Technical options are listed for code organisation, programming language, interfacing and containerisation, data organisation, storage and licensing.Also, the role of the MCRA web platform is discussed. The report ends with a suggested approach and next steps, includinga discussion on the need for a governance structure for sustainable development of Open MCRA.