Grant Lobdell is the Senior Chemist and Lab Manager at Dyne Fire Protection Labs. His article Dry Sprinkler Testing Requirements was published in the September 2017 edition of FPC magazine. 

Excerpt from the article:

The 2017 edition of the National Fire Protection Association (NFPA 25) “Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems,” Section states, “Except as permitted by and, all antifreeze systems shall utilize listed antifreeze solutions.”  Furthermore, the next section of the same standard states, “For systems installed prior to September 30, 2012, listed antifreeze solutions shall not be required until September 30, 2022 where one of the conditions [in the following sections] is met.”  As the September 2022 deadline for the requirement to use a listed antifreeze solution approaches with no such product available to date, alternative methods such as heated valve enclosures, heat tracing, and insolation for freeze protecting water-based fire protection systems could become more popular.