DOWFROST HD Concentrate in a 5 gallon pail is a propylene glycol-based heat transfer fluid that is widely used for secondary cooling and heating applications, for freeze and burst protection of pipes, and for various deicing, defrosting, and dehumidifying applications. It contains specially formulated boosted packages of industrial inhibitors that help prevent corrosion. It consists of 94% propylene glycol and 6% additives. DOWFROST HD Concentrate in a 5 gallon pail is especially useful in applications where toxicity is a concern, propylene glycol fluids are used because of their low acute oral toxicity vs. the moderate acute oral toxicity of ethylene glycols. Examples include applications where contact with drinking water is possible, food processing applications where accidental contact with food or beverage products could occur, and applications in localities where propylene glycol use is mandated by law.