Quick view Douglas Products Douglas HTF Inhibited Propylene Glycol MSRP: $36.15 - $189.43 Douglas HTF Inhibited Propylene Glycol in 1 Gallon Containers Recommended for: Block Ice MachinesCirculating Beer SystemsClosed Water Loop Refrigeration SystemWood Boiler SystemClosed Loop... MSRP: $36.15 - $189.43 Quick Add Add to Wish list