本规范涵盖了由异氰酸酯组分和其他组分组成的聚氨酯系统，这些组分含有多元醇和其他组分，当混合和固化时，可生产热固性、刚性、多孔产品。

This specification covers polyurethane systems consisting of an isocyanate component and other components containing a polyol and other ingredients which, when mixed and cured, produce thermosetting, rigid, cellular products.