Which statement best describes Limited-Combustible materials?

• A. Refers to a building construction material not complying with noncombustible that, in the form used, has a potential heat value not exceeding 3500 Btu/lb and includes either: (1) base noncombustible with surfacing <=1/8 in and flame spread <=50; or (2) forms with thickness used having neither a flame spread index greater than 25 nor evidence of continued progressive combustion.
• B. Is identical to noncombustible materials.
• C. Only applies to metal-based materials.
• D. Relies solely on NFPA 259 for classification.

Answer: (D)

Limited-Combustible materials are finishes or components that can burn but are designed to release limited heat and slow fire growth. The way they are classified in the Life Safety Code is through the test method defined in NFPA 259, which assesses the potential heat output of building materials. If a material meets the NFPA 259 criteria, it is designated as limited combustible. This is why the statement that it relies on NFPA 259 for classification is the best description.

Other options don’t fit because limited combustible is not identical to noncombustible, it isn’t restricted only to metal-based materials, and the key basis for classification is the NFPA 259 test, not simply a generic heat-value or a different standard.