How does iso/dis 14042 on life cycle impact assessment accommodate current best available practice?

This article discusses to which extent the forthcoming ISO standard on life cycle impact assessment (ISO/DIS 14042) will be able to accommodate current best available practice in this field. There is, particularly, the risk that the requirement of scientific validity for public comparative assertions cannot be met sufficiently so that the standard may become counterproductive. It is concluded that current best practice for most of the impact categories is compatible with the forthcoming standard. However, difficulties will arise with the toxicity categories, in particular with human toxicity. There is no encompassing indicator is available which does not involve weighting between subcategories. A major improvement would be if, for weighting within categories, internationally accepted value choices would be established as a sufficient condition for public comparative assertions.