ISO 9028:2006规定了用硝酸或硝酸和硫酸混合物分解生橡胶和橡胶制品的方法。本国际标准通常适用，但在存在潜在挥发性元素或元素组合（即As、Sb、Bi和Zn+Cl、Cu+Cl和Pb+Cl）的情况下，本标准至关重要。这在这些情况下很有用，因为温度较低，挥发损失较小。 如果不建议使用ISO 247《橡胶-灰分测定》，则将使用这些方法来产生金属测定溶液，例如痕量金属。这些方法可防止挥发性金属衍生物的损失和不溶性金属硅酸盐的形成（含锌卤化橡胶或填充二氧化硅的橡胶在干灰化过程中可能会产生这种情况）。

ISO 9028:2006 specifies methods for disintegration of raw rubber and rubber products by nitric acid or by a mixture of nitric and sulfuric acids. This International Standard is generally applicable, but is essential where potentially volatile elements or combinations of elements are present (i.e. As, Sb, Bi, and Zn + Cl, Cu + Cl and Pb + Cl). It is useful in these cases because lower temperatures are involved which result in less loss by volatilization. These methods will be used in order to produce solutions for the determination of metals, for example as traces, if the application of ISO 247, Rubber - Determination of ash, is not advisable. These methods prevent loss of volatile metal derivatives and the formation of insoluble metal silicates (which may result during dry ashing of halogenated rubbers containing zinc or of rubbers filled with silica).