Quick view Douglas Products Douglas HTF Inhibited Propylene Glycol MSRP: $165.05 - $864.97 Douglas HTF Inhibited Propylene Glycol in 1 Gallon Containers Recommended for: Block Ice Machines Circulating Beer Systems Closed Water Loop Refrigeration System Wood Boiler System Closed... MSRP: $165.05 - $864.97 Quick Add Add to Wish list