'scale-preventing' originates from modern English as a compound of 'scale' + 'prevent' + the suffix '-ing'. 'scale' ultimately comes (via Middle English) from Old Norse roots meaning 'shell' or 'flake', where it later developed the sense of a deposit or crust; 'prevent' originates from Latin 'praevenire' via Old French 'prevenir', where 'prae-' meant 'before' and 'venire' meant 'to come'.

'scale' shifted from Old Norse/Middle English meanings of 'shell' or 'flake' into a geological/technical sense of mineral deposits (e.g. limescale). 'prevent' passed from Latin 'praevenire' to Old French 'prevenir' and Middle English forms (e.g. 'prevenen'), becoming modern English 'prevent'. The compound 'scale-preventing' is a recent English formation combining these elements to describe products or actions that stop scale formation.

Initially, 'scale' meant 'shell' or 'flake' and 'prevent' meant 'to come before'; over time 'scale' acquired the specific technical sense of mineral deposits, and the compound evolved to mean 'intended to stop the formation of such deposits'.