Quick view Douglas Products Douglas HTF Inhibited Propylene Glycol MSRP: £34.88 - £182.80 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: £34.88 - £182.80 Quick Add Add to Wish list