Quick view Douglas Products Douglas HTF Inhibited Propylene Glycol MSRP: $4.234 - $22.188 Douglas HTF Inhibited Propylene Glycol in 1 Gallon Containers Recommended for: Block Ice MachinesCirculating Beer SystemsClosed Water Loop Refrigeration SystemWood Boiler SystemClosed Loop... MSRP: $4.234 - $22.188 Quick Add Add to Wish list