Quick view Douglas Products Douglas HTF Inhibited Propylene Glycol MSRP: $71.34 - $373.84 Douglas HTF Inhibited Propylene Glycol in 1 Gallon Containers Recommended for: Block Ice MachinesCirculating Beer SystemsClosed Water Loop Refrigeration SystemWood Boiler SystemClosed Loop... MSRP: $71.34 - $373.84 Quick Add Add to Wish list