'chlorine-based' originates from English as a compound of 'chlorine' and 'based'. 'Chlorine' ultimately comes from French 'chlore' and Greek 'chloros', where 'chloros' meant 'greenish-yellow'; 'based' comes from Latin/Greek via Old French 'base' (from Greek 'basis'), where 'basis' meant 'foundation'.

'chlorine' changed from French 'chlore' (itself from Greek 'chloros') into the modern English 'chlorine', and 'based' developed from Latin/Greek 'basis' through Old French 'base' into English; the modern compound 'chlorine-based' arose in English by combining these elements to describe substances founded on or containing chlorine.

Initially, the components referred literally to the chemical 'chlorine' and the idea of a 'base' or foundation; over time the compound came to mean 'containing or derived from chlorine' (i.e., 'chlorine-based' as an adjectival classification of products or processes).