For heating systems requiring freeze protection as well as corrosion prevention, count on Hercules Cryo-Tek™ anti-freeze. Its exclusive triple protection inhibitor system also protects against mineral deposits and sedimentation. Cryo-Tek is designed for use in hydronic heating and cooling closed-loop systems, most solar heating systems, snow melts, radiant heat and general plumbing systems. Non-flammable, odorless, non-toxic, non-irritating, and compatible with Hercules boiler stop-leak and heating system cleaners. (Check with system manufacturer for compatibility).