Day 1 Part 4 covers reports from tools used for providing search and browsing functionalities across ontology collections with the NFDI4Chem ontology service and ontology development and curation with ROBOT or the ontology development kit ODK. The workshop provided a comprehensive overview of past and current activities of chemistry ontology projects, tools for ontology engineering and the application and curation of ontogologies in research data management. Recording Day 1 Part 4 of the 1st International Ontologies4Chem Workshopy organized by NFDI4Chem - the chemistry consortium in the NFDI. Details: https://doi.org/10.25798/frnp-sn04