Quick view Douglas Products Douglas HTF Inhibited Propylene Glycol MSRP: $13.347 - $69.945 Douglas HTF Inhibited Propylene Glycol in 1 Gallon Containers Recommended for: Block Ice MachinesCirculating Beer SystemsClosed Water Loop Refrigeration SystemWood Boiler SystemClosed Loop... MSRP: $13.347 - $69.945 Quick Add Add to Wish list