关于二丁基锡化合物的第20(5)条，(a)款规定了混合物和供应给公众的物品中锡的浓度限制。如果物品上涂有二丁基锡化合物的油漆层，锡的浓度应如何计算：仅计算干油漆层的锡浓度，还是计算涂漆物品的重量？

关于二丁基锡化合物的第20(5)条，(a)款规定了混合物和供应给公众的物品中锡的浓度限制。如果物品上涂有二丁基锡化合物的油漆层，锡的浓度应如何计算：仅计算干油漆层的锡浓度，还是计算涂漆物品的重量？

Entry 20(5) on dibutyltin compounds, paragraph (a) imposes a concentration limit for tin in mixtures and articles for supply to the general public. If a paint layer with dibutyltin compound is applied to the article, how should the concentration of tin be calculated: in the dry paint layer alone, or across the weight of the painted article?

限制合规性评估基于整件涂漆物品的重量，而非干漆层的重量。此方法遵循《物品中物质要求指南》第3.2.3.1节表5中的方案。更多详情，请参阅关于附件XVII以及“物品”、“复杂物体”和“物品部件”概念的问答1564。

Compliance with the restriction is assessed based on the weight of the entire painted article and not based on the weight of the layer of dry paint. This approach follows the scenarios from the Guidance on requirements for substances in articles, Table 5 under subchapter 3.2.3.1. For further details see Q&A 1564 on Annex XVII and concepts of ‘article’, ‘complex object’ and ‘parts of articles’.