We provide an overview of the use we make of ontologies at the Royal Society of Chemistry. Our engagement with the ontology community began in 2006 with preparations for Project Prospect, which used ChEBI and other Open Biomedical Ontologies to mark up journal articles. Subsequently Project Prospect has evolved into DERA (Digitally Enhancing the RSC Archive) and we have developed further ontologies for text markup, covering analytical methods and name reactions. Most recently we have been contributing to CHEMINF, an open-source cheminformatics ontology, as part of our work on disseminating calculated physicochemical properties of molecules via the Open PHACTS. We show how we represent these properties and how it can serve as a template for disseminating different sorts of chemical information.