The EuroMix toolbox is a web-based platform including data and models accessible to all key-actors in risk assessment and risk management. The platform includes or links to relevant models to provide estimates of hazard, exposure and risk. The software platform builds on the Monte Carlo Risk Assessment (MCRA) system and is implemented as MCRA version 9.0. MCRA 9.0 is available at https://mcra.rivm.nl. MCRA 9.0 is a modular system contains many models for exposure, hazard and risk assessment. Validation of the toolbox as a whole can be broken down into the validation of different parts. In this report two types of validation are described, internal and external. Internal validation is concerned with checking the software for programming errors and comparing the functionality and outputs of the models against previously released versions. For internal validation all modules of the toolbox are included. External validation compares the functionality and output of the models against external values generated by another existing software platform. Given the wide functionality of the EuroMix toolbox this is a non-trivial task for the toolbox as a whole. In this document external validation is restricted to the aggregation of dietary and nondietary exposures in the Exposures module. This is compared with similar calculations in the US software SHEDS-HT.