UMSA is an untargeted mass-spectrometry analysis service from RECETOX (Research Centre for Toxic Compounds in the Environment at Masaryk University) in the Czech Republic. The service is evolving to a key component of the emerging EIRENE ESFRI. By means of the integration in EOSC, uniform access to data and computing resources are provided, scaling the service to the target European-wide user community. Typically, mass spectrometry is done in a targeted way to confirm or disprove the presence of a specific compound in a sample. On the contrary, we aim at processing data to correlating the whole spectra (ie. all the present compounds) with other data (social, medical, other sample analyses, etc.) to work with more complex hypotheses of environmental impacts on human health. The platform is built on the well-known Galaxy framework, and it includes dozens of open-source tools tightly integrated into fully functional workflows.