Nu-Calgon 4207-47 - 8 FL OZ BOTTLE Liquid Ice Machine Cleaner is a 75% phosphoric acid of the highest food-grade quality. It is fast acting yet very safe to use and it does not give off any harsh fumes. Because of its 75% phosphoric acid content, it is the most concentrated ice machine cleaner in the market. It has a specific gravity of 1.63 and weighs 13.6 per gallon. Usage rate is 8 fluid ounces with three gallons of water.