Quick view Douglas Products Douglas HTF Inhibited Propylene Glycol MSRP: $58.52 - $306.67 Douglas HTF Inhibited Propylene Glycol in 1 Gallon Containers Recommended for: Block Ice MachinesCirculating Beer SystemsClosed Water Loop Refrigeration SystemWood Boiler SystemClosed Loop... MSRP: $58.52 - $306.67 Quick Add Add to Wish list