This is 100% concentrated non-toxic propylene glycol formulated with the proper dosage of Treatment Solution 101 Anti-Corrosion Chemical already in it.  Being pure product, adequate burst protection can be achieved with 35%-40% of your system filled with our product.  Compare that to competitors where you might need to fill 50% + of the system with their product to achieve the same burst protection.  Most importantly:  our product is unsurpassed in CORROSION PROTECTION.  No Freeze 201 also solves the problem of monitoring corrosion inhibitor concentration (level) in the system.  We add a red indicator dye to the No Freeze 201 product that easily tells you if the system is adequately protected from corrosion.  When the red color of your water is observed faint or disappears, indicating a low level, add an appropriate dose of Treament Solution 101 and you are all set.  It is that simple. Most competitors talk a lot about freeze/burst protection.  The truth is we are all selling glycol.   But are they providing your system with the proper corrosion protection?   If you really want to know who you are buying from ask these two questions: 1) Is the product pure glycol? 2) then ask the specifics in regards to the corrosion and sludge/scale inhibitor package.

Freeze point is defined as the onset of crystal formation on a non-operating, stagnant system.

A quality glycol refractometer would be used to determine exact system protection limits.

Make sure your refractometer is measuring propylene glycol.

Automotive antifreeze testing instruments may or may not be compatible.

Automotive antifreeze is NOT suitable or applicable for your boiler/stove!!

Many manufacturers advertise a burst point as a freeze point.  Burst point is what is critical but facts should still be presented correctly.