StatusTo DoData SourceNLMUpdate FrequencyDescriptionSource LinksDownloadAPIUpdate FrequencyLicensingTable InfoDescriptionCould be useful for linking between different types of chemical IDs (i.e. CAS and UNII).✋ Request this data sourceSource LinksDownloadDownloadsPubChem is an open access database with most of the data available for download. Exceptions may exist in cases where licensing agreements prevent our data contributors from allowing bulk downloads of some data sets.pubchemdocs.ncbi.nlm.nih.govAPIUpdate FrequencyLicensingTable Info