As a rule, water soluble products may be winterized to about 0ºF by adding 15 gallons per drum of either Ethylene Glycol, or a 50-50 blend of Ethylene Glycol / Methanol. Most scale inhibitors will not tolerate an alcohol if used in high proportions. However, it appears that the above 50-50 blend is fairly well tolerated (and less expensive). Oil soluble products should not have to be winterized depending on the quality of the aromatic solvent used.