Commercial/Institutional Supply Places
Will not ship STPP laden laundry products to NYS. Ecolab has written clearly on packages of product (laundry detergent, bleaches, etc...)that contain phosphates it is not offered for sale in NY. Have not looked since the ban was announced regarding commercial dishwasher products.
Chemistry Store fills our orders for phosphates without any problems, so one assumes other sources for domestic use are fine.
As for using STPP, yes one does have a stash and uses phosphates though find myself tapering off.
First much of my stash of vintage laundry detergents are laden with phosphates. Dash, Gain, Burst, FAB, Punch, VIM, etc... all have more than enough of the stuff to get things done. Will add a bit of STPP when using modern liquid detergents, and of course when using soaps (P&G, Kirkman's, and Fels), and the NOS vintage Persil which is mainly washing soda, sodium perborate and soap.