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  • Optimum freeze or burst protection
  • Fully inhibited to prevent corrosion
  • Non-flammable
  • Uses renewable resourced propylene glycol
  • Low in acute oral toxicity
  • Colored blue for easy leak detection


Freez-Kontr’l is a formulation of propylene glycol, dipotassium phosphate corrosion inhibitor and de-ionized water. The fluid is colored blue to aid in leak detection. It has an operating temperature range from below -60°F to 230°F and solutions in water provide freeze protection to below -60°F and burst protection to below -100°F.

Freez-Kontr’l is nearly odorless and the product of choice when contact with potable water is possible. The ingredients used in its manufacture are GRAS (generally recognized as safe), under Title 21, Part 182 of the US Code of Federal Regulations, where accidental or incidental contact with potable water could occur.

  • Freez-Kontr’l - provides greater than -60ºF freeze protection and greater than -100ºF burst protection.
  • Freez-Kontr’l 95/5 - a fully concentrated (~100%), inhibited propylene glycol product.
  • Freez-Kontr'l 50 - A ready-to-use 50% propylene glycol formulation for use in closed loop systems. Inhibited.
  • Freez-Kontr’l 35 - formulated with 35% propylene glycol for use in hydronic and refrigeration systems.
  • Freez-Kontr’l FG - a certified USP, food grade propylene glycol product at ~100% concentration. Inhibited. NSF registered.
  • Freez-Kontr’l FG Clear - a non-dyed, full concentrate propylene glycol heat transfer fluid, NSF listed as an HT-1 fluid for use in food and beverage equipment. Inhibited.
  • Freez-Kontr’l HD Heavy Duty - a heavy duty propylene glycol with pink coloration, for use in hydronic and solar applications with higher operating temperatures. Inhibited
Packaging Size Part Number Additional Info
1 gallon bottle 4188-07
5 gallon pail 4188-05
55 gallon drum 4188-02
Freez-Kontr'l 35, 5 gallon pail 4188-16
Freez-Kontr'l 35 - 55 gallon drum 4188-35
Freez-Kontr'l 95/5 - 5 gallon pail 4188-06
Freez-Kontr'l 95/5 - 55 gallon drum 4188-03
Freez-Kontr'l 50, 5 gallon pail 4188-17


This product must be used in accordance to the following directions by HVACR professionals only.

  1. Clean new or lightly corroded existing systems with Nu-Calgon System Cleaner (4370-08) prior to installation of Freez-Kontr’l. Do not use with galvanized steel.
  2. Extensively corroded existing systems should be cleaned using an inhibited acid such as Season Start Scale Remover or Liquid Scale Dissolver. Job should be handled by an experienced serviceman. All necessary replacements and repairs should be made.
  3. The concentration of required glycol-based Freez-Kontr’l will depend on the kind of protection needed. There are two types of protection: burst protection and freeze protection. Burst protection prevents bursting or other mechanical damage, but it is not enough to keep solution pumpable. Freeze protection requires more glycol, and it prevents the formation of ice crystals at the lowest temperature experienced by the fluid. This assure fluid can be pumped at the lowest experienced temperature.
  4. Typically, ice storage systems, fire sprinkler systems and intermittently run hydronic systems may be fine with burst protection while chilled water and lawn sprinkler systems need freeze protection.
  5. See the chart and select the lowest expected ambient temperature, then go to a temperature 5ºF colder to assure protection. Decide on type of protection, and identify the solution percentage that must be made up of Freez-Kontr’l.
  6. Calculate or establish system volume in gallons, and multiply this volume by the percentage identified above. This will tell you the number of gallons of Freez-Kontr’l required.
  7. For optimum corrosion protection, a minimum concentration of 30% is recommended.

Product Information:

Literature Downloads

Download the product bulletin and other relevant literature here.


Download a low resolution file of the product label here.

Product Safety

RTK Information

2611 Schuetz Rd. St. Louis, MO 63043
  • Telephone: 800.554.5499
  • Email:
  • Hours: Mon–Fri: 8:00am - 5:00pm (Central Time)

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