ISO 19821:2017规定了确定天然纤维增强塑料复合材料（NFC）桥面板和用作楼梯踏板的桥面板跨度额定值的程序，前提是楼梯踏板由与桥面板相同的材料和加工技术制成。本文件涵盖了性能测试方法、验收标准和跨度额定值的确定。其目的是为允许可燃结构的外部应用中使用的甲板的代码识别奠定基础。

ISO 19821:2017 specifies the procedures to establish a span rating for natural fibre-reinforced plastic composite (NFC) deck boards and deck boards used as stair treads, provided that the stair treads are produced from the same materials and processing techniques as the deck boards. This document covers test methods of performance, acceptance criteria and determination of span rating. It is intended to establish the basis for code recognition of deck boards used in exterior applications where combustible construction is allowed.