This Outline of Investigation covers requirements for the performance of antifreeze solutions for fire sprinkler systems. These solutions are intended for use in wet pipe sprinkler systems subject to freezing for installation in accordance with the manufacturer??s design and installation instructions@ Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes@ NFPA 13D@ Standard for the Installation of Sprinkler Systems in Low-Rise Residential Occupancies@ NFPA 13R@ and the Standard for Installation of Automatic Sprinkler Systems@ NFPA 13; and inspected@ tested and maintained in accordance with the Standard for Inspection@ Testing and Maintenance of Water Based Fire Protection Systems@ NFPA 25. This Outline of Investigation does not contain requirements to evaluate the risk associated with products of combustion of antifreeze solutions.