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Food Grade and Technical Grade! What are the key differences?

Teknisk information


  1. CoolFlow NTP uses Technical Grade Mono Propylene Glycol and CoolFlow NTP-HT1 uses USP Grade MPG as its base constituent. Technical Grade and USP Grade both have exactly the same toxicity rating. When USP Grade is mixed with any inhibitor, including an HT-1 classified inhibitor, then the USP Grade becomes null and void and reverts to Technical Grade MPG. I.E. there is no real point in starting off the formulation with USP MPG, at much greater expense to the customer, only to corrupt the USP classification.
  2. Technical Grade MPG and USP Grade MPG are made in the same vessels and often at the same time. The key difference between them is the vessels used to transport and store the product after manufacture. USP Grade MPG can only be stored in specific tanks that have been pre-cleaned and certified to a pharmaceutical standard. It is important to note that, to the best of our knowledge, no cooling system (on the coolant side) is USP certified. Subsequently any USP rating would be null and void once it is pumped in to the cooling system. I.E. it reverts to Technical Grade MPG.
  3. As mentioned above standard CoolFlow NTP is formulated using well proven corrosion, scale and biological inhibitors, but not all have been registered with NSF or its UK equivalent InS (both of these are independent, non-governmental registration only bodies). CoolFlow NTP-HT1 can incorporate only two registered corrosion inhibitors, but not at the same time. The 1st inhibitor is very good but not suitable for use with hard-water. Therefore, we mostly use the 2nd inhibitor when making CoolFlow NTP-HT1, which is hard-water tolerant. Neither of these inhibitors will provide the same overall protection as those provided through the synergistic inhibitor pack within standard CoolFlow NTP.
  4. There are no suitable biocidal inhibitors registered with NSF or InS, that can be included in a heat transfer fluid formulation which meets HT-1.Therefore, if CoolFlow NTP-HT1 is selected over standard CoolFlow NTP, there will always be a potential for biological ingress and contamination.Bugs will actively contaminate and consume MPG at concentrations below 25% v/v, as can occur in all cooling systems from time to time. So whilst it is possible to achieve a (temporary?) HT-1 rating for incidental food contact, the actual rating may well be far less safe over a period of time.


Managing Director Steve Hickson, Liquitherm Technologies Group Ltd.
April 2016