Renew Descaling Powder contains a synergistic blend of organic acids that give outstanding scale removal. Renew is Listed with NSF. It has been tested, evaluated and passed the most stringent toxicology and corrosivity standards. The ingredients and formulation of Renew are safe, leave no harmful residues and do not cause corrosion within the coffee machine. Safe to use on aluminium, brass and stainless steel. Designed for espresso machines, boilers and coffee brewers. This product can also be used in kettles, urns and bain-maries.Instructions for coffee machine Add contents of sachet to 1L of warm water, dissolve, and then pour into water tank. Remove filter holder and turn machine on. Place cup under brew spout and run out about 1 cup of the descaling solution. Run about a ¼ cup out through the steam arm. (For fully automatic machines run all the solution through the steam wand and set on hot water not the steam setting). Allow to stand for 15 minutes, and then repeat the process. Repeat the entire process until all the solution is used up. Rinse thoroughly by flushing one tank of clean fresh water through the system exiting through the brew head and the steam wand.