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BioTherm Fluids AF® Information


  • Clear Liquid
  • Mild/No Odor
  • pH: 9
  • Specific Gravity: 1.15
  • Freeze Point: -34 °C (-30 °F)
  • Viscosity: 11 (@ 20C cSt)
  • Conductivity: 1.7 mS


Derived from agricultural materials or bio-based processes, this environmentally friendly product is engineered to match the freezing point performance of conventional antifreeze products based on glycols, but with the following advantages:

  • Biobased / BioPreferred
  • NSF Registered (HT1)
  • Tested to ASTM D1384
  • Lower BOD/COD
  • No Glycols
  • Readily Biodegradable
  • Non-Toxic
  • Designed for Environmentally Sensitive Applications


nsf logoNSF Registered
This product is acceptable for use as a heat transfer fluid where there is possibility of incidental food contact (HT1). 

Won’t Dry Out
Due to its viscous nature and hygroscopic character, AF will not dry out after initial application, making it effective for extended periods of time as an antifreeze and a dust suppressant.


BioTherm Fluids® AF is a 100% certified USDA Biobased Product as tested by ASTM D6866 through the USDA BioPreferred® Program. AF is non-toxic, non-corrosive and is fully biodegradable, offering a lower BOD/COD than glycol. 

BioTherm Fluids® AF has been tested to OECD 310 with results showing it is "readily biodegradable" meaning that there is unequivocal evidence that AF is rapidly mineralized to inorganic components and biomass. AF also meets the definitions of "inherently biodegradable" and "ultimately biodegradable" meaning that there is a reasonable expectation that they will eventually be completely mineralized in aerobic environments.


BioTherm Fluids® AF is formulated from complex carbohydrates derived from renewable resources and/or process side streams that facilitate cost-effective and not subject to the market swings of glycols.


AF is a glycerin based product, DO NOT use testers designed for glycols. Freeze point range can quickly be determined by a special tester (pictured left) available from Orison or more accurately by a refractometer (Brix pictured right) - Brix Value Chart below.

AF is slightly more viscous than conventional antifreeze materials. As such, it adheres to particle surfaces and clings to transportation and conveying equipment with little run-off and settling. This prevents freezing, clumping and sticking, and keeps product moving freely.


Although no negative effects are expected, mixing antifreeze/coolants is not recommended due to varying freeze point depressants and corrosion inhibitor technologies which leads to difficulties determining actual freeze point protection and corrosion inhibition properties. Use only BioTherm Fluids® AF in the system.

The chart below is supplied as a guide for diagnostic / maintenance purposes. The values are calculated values and are only approximations. AF is ready-to-use and not recommended to be diluted as the result would weaken the corrosion inhibitor package. Custom blends are available.

IceClear AF% (Weight) Brix Value (Refractometer) Freeze Point F/C Boiling Point F/C Specific Heat @35F ViscositycST @68F (20c)
100 46.5 -30/-34 228/109 .74 10.8
90 42.1 -17/-27 225/107 .77 7.9
80 37.5 -6/-21 222/106 .81 5.5
70 33.1 2/-17 219/104 .83 4.1
60 28.7 9/-13 218/103.5 .85 3.2
50 24.1 15/-10 217/103 .87 2.5


*Addition of TRAMFLOC® 1142 FOAM CONTROL AGENT may be beneficial for some applications. TRAMFLOC® 1142 FOAM CONTROL AGENT is a nonionic, nonsilicone, food grade defoamer. TRAMFLOC® 1142 FOAM CONTROL AGENT performs well in a wide range of pH and temperatures. All ingredients used in the manufacture of TRAMFLOC® 1142 FOAM CONTROL AGENT are either GRAS or listed in the Code of Federal Regulations: Title 21, Section 173.340. Recommended use at 1 oz/ 10 - 20 gallons of system fluid.


Note: BioTherm Fluids® AF is designed as a ready-to-use. It may be diluted, however, it may weaken the corrosion inhibitor package. Diluting this product more than 20% with water may be subject to bacterial contamination.