Calgon (Cal-GONe - get it?) was invented by Hagen corporation as water treatment chemical for use with steam boilers.
Rest as they say is history.
https://historicpittsburgh.org/islandora/object/pitt:US-QQS-mss693/viewer
Phosphates are such excellent builders or additives for laundry and dishwashing (among other things) tons of the stuff was in added to laundry soaps/detergents and later automatic dishwashing detergents. This happened on both sides of pond but wasn't to last.
By 1970's in both North America and Europe governments began looking to reduce if not ban use of phosphates in domestic and or commercial cleaning products on environmental grounds.
In Europe Calgon and other such products were heavily promoted and or used due to areas having water sometimes hard enough to chip teeth upon. But there was also the dominance of immersion and other heaters in washing machines and dishwashers that became encrusted with hard water mineral build up that lead to malfunctioning.
In North America Calgon was flogged as the "ancient Chinese secret" to a whiter and cleaner wash (largely at first due to properties of phosphates).
In Europe it was more about protecting washing machine heating elements and some other bits.
As governments across Europe forced reduction then banned phosphates in laundry detergents and other products chemists at Henkel, Lever Bros. (Unilever) and elsewhere began intensely working on products that delivered same or better results in hardest water using builders other than phosphates along with other things such as surfactants.
Results are at least with top or even middle shelf products across Europe you don't need additives such as Calgon. Long as consumers dose detergent or whatever product correctly (suited to local water hardness), nothing else is required far as coping with hard water issues.
This has not stopped makers of Calgon from flogging their product despite consumer groups and others saying it's just not really necessary.
