NFPA 703-2018 Standard for Fire-Retardant–Treated Wood and Fire-Retardant Coatings for Building Materials. Class B fre-retardant coatings shall reduce the fame spread index to greater than 25 but not more than 75 and have a smoke developed index not exceeding 200 where applied to the applicable substrate, building material, or species of wood when tested in accordance with ASTM E84 or ANSI/UL 723. 5.3.2 Where fre-retardant coatings are to be subjected to sustained humidity of 80 percent or more or exposure to the weather, certifcation by a testing laboratory shall be required to indicate that there is no increase in listed classifcation when subjected to the “Standard Rain Test” described in ASTM D2898, Standard Test Methods for Accelerated Weathering of Fire- Retardant-Treated Wood for Fire Testing, (Method A). 5.4 Maintenance of Protection. Fire-retardant coatings shall possess the desired degree of permanency and shall be main‐ tained to retain the effectiveness of the treatment under the service conditions encountered in actual use. 5.5 Labeled. 5.5.1 The fre-retardant–coating material shall be listed and labeled to indicate conformance with the requirements in Sections 5.2 through 5.4. 5.5.2 The manufacturers’ instructions for application shall be affxed to each container of the fre-retardant–coating material.
A.3.2.4 Listed. The means for identifying listed equipment may vary for each organization concerned with product evalua‐ tion; some organizations do not recognize equipment as listed unless it is also labeled. The authority having jurisdiction should utilize the system employed by the listing organization to identify a listed product. N A.3.3.1 Fire-Retardant Clothing. The effcacy of fre-retardant coatings to decrease fame spread index is normally assessed by testing in accordance with ASTM E84, Standard Test Methods for Fire Tests of Building Construction and Materials, or ANSI/UL 723, Standard for Test for Surface Burning Characteristics of Building Materials. A.5.1 This section does not address the use of fre-retardant coatings as a thermal barrier. A.5.2.1 Certain coatings might not be suitable for high- humidity occupancies or for other occupancies where combus‐ tible dust or oily residue deposits might accumulate, affecting the ability of the coating to adhere to the substrate material. A.5.3.1 The fame spread index is expressed numerically on a scale for which the zero point is fxed by the performance of inorganic-reinforced cement board and the 100 point (approx‐ imately) is fxed by the performance of red oak fooring.NFPA 703 pdf download.