The CAS No is the ‘chemical abstracts service registry number’, which is a unique numeric identifier specific to each substance and its structure.
Is éard atá san Uimh. CAS “uimhir chláraithe sheirbhís na gcoimrithe ceimiceacha”, ar sainaitheantóir uimhriúil uathúil a bhaineann go sonrach le gach substaint agus a struchtúr é.