BS 476 Part 7产品火焰表面延伸等级测试用于评定产品阻燃等级性能。BS 476 Part 7标准共有四个等级：class 1，class 2，class 3，class 4，其中class 1阻燃性能最好，class 4火灾风险最大，不能用于建材上。更多具体BS476-7阻燃等级测试，请咨询400-666-7290。
BS 476-7: Fire tests on building materials and structures-Part 7 method of test to determine the classification of the surface spread of flame of products.
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