If you are trying to figure out when to use DOWFROST™ vs DOWFROST™ HD Heat Transfer Fluid you are in the right place.

Let’s start with what they have in common.

Both are made with pharmaceutical grade DOW PuraGuard™ Propylene Glycol USP/EP and when diluted with purified water, provide freeze protection and low toxicity. Plain glycols or “home brews” can’t neutralize all glycol degradation acids and make water up to ten times more corrosive. Dow’s corrosion inhibitors and additives passivate metal surfaces to prevent corrosion and neutralize degradation compounds preventing pH drop. Dow’s formula also has thermal-oxidation stability that provides long-term protection.

Now, how they are different.

Both fluids are low in acute oral toxicity, making them suitable for use where incidental contact with drinking water is possible. However, the ingredients in DOWFROST have been cleared by the FDA for use as food additives and listed as Generally Regarded As Safe (GRAS). DOWFROST is also listed as chemically acceptable by the United States Department of Agriculture (USDA) for certain food processing applications.

DOWFROST HD on the other hand has a corrosion inhibitor that does not meet the FDA requirements and is needed for systems that contain copper piping. Also, the recommended use temperature range is higher for the DOWFROST HD.

Here are some applications for DOWFROST:

Applications Used In Benefits
Cooling Liquid Foods ​Breweries, Wineries, Dairies, Fruit Juice Processors, Restaurants, Bars, & Vending Machines Low Toxicity, Low Flammability, Dependable Temperature Control, Lower Temperature Capabilities, Cost Savings Through Increased Production Times (Ability To Bottle Faster)
Fermentation Cooling Breweries, Wineries, Refrigeration of Yeast Bulk Storage Tanks Low Toxicity, Low Odor, Virtually Tasteless, Will Not Affect Foaming Or Fermentation Properties, Dependable Temperature Control
Packaging Carbonated Beverages Sparkling Wines, Champagne, Beer, & Other Carbonated Beverages Low Toxicity, Prevents Loss of Carbonation, Allows Removal of Trapped Sediment (Champagne)
Plastic Bottle Blow Molding ​Dairies, Food Processors, & Packaging Companies Low Toxicity, Cools The Mold Faster To Increase Production, Allows Flash To Be Removed More Quickly and Cleanly, Improved Quality
Ice-Making Ice Production Plates ​Low Toxicity, Freeze Water More Quickly
Refrigeration Coil Defrosting ​Walk-in Freezers, Chiller Units, Freezing Tunnels, & Basket Freezing Units ​Lowers Freeze Point, Preventing Frost Formation (Allowing Compressor Motors To Operate More Efficiently), Fluids Are Easy To Regenerate & Reconcentrate (Allows Less Interruption Of Production)

DOWFROST HD is engineered for closed loop HVAC systems with operating ranges of -50ºF to 325ºF. The industrial corrosion inhibitor is dyed yellow for leak detection. DOWFROST HD does not have FDA or NSF approval because it contains a supplemental non-food grade raw material that is needed for copper piping. Solutions of this in water provide freeze protection to below -50°C (-60°F) and burst protection to below -73°C (-100°F). It is widely used within the HVAC industry or wherever low toxicity, environmentally friendly heat transfer fluids are needed such as schools and hospitals.

Compared to DOWFROST, DOWFROST HD has a higher maximum operating temperature, higher reserve alkalinity, and greater thermal stability. While DOWFROST is considered the standard propylene glycol-based fluid for most applications, DOWFROST HD is specified to extend fluid life where service temperatures are higher, and the likelihood of thermal degradation is greater. It is sometimes also used in less demanding applications because the heavy-duty inhibitors last longer, and maintenance requirements can be reduced. DOWFROST HD is particularly well-suited for HVAC applications because its inhibitor package offers additional corrosion protection for systems containing copper components.


Recommended Use Temperature Range -45°C (-50°F) to 120°C (250°F) -45°C (-50°F) to 160°C (325°F)
% DOW PuraGuard™ Propylene Glycol USP/EP 96% 94%
NSF HT1 Compliant (where there is possibility of incidental food contact) YES NO
Generally Regarded As Safe (GRAS). YES (clear color only) NO

Contact Lentus to order DOWFROST and DOWFROST HD by calling 270-765-2212 or emailing orders@LentusLLC.com.

Get in touch