The purpose of this International Standard is to describe a method for assessing genotoxic effects (chromosome breakage or dysfunction of the mitotic spindle) of soils or soil materials on the secondary roots of higher plants: Vicia faba (broad bean). This method allows the assessment of genotoxicity (toxicity for genetic material) for soils and soil materials like compost, sludge, waste, fertilizing matters. In the context of assessment of the quality of soils and soil materials, it appears necessary to determine in vivo their genotoxic potential induced by pollution or by a decontamination process. Genotoxic agents have the ability to damage the genome of living organisms or to interfere with its functioning, but they are not always detected by chemical analysis or classical eco-toxicological tests. Actually, genotoxic effects are often observed at sub-lethal concentrations, where no toxic effect (for example survival or growth) can be observed in the short term, but some long term effects are feared in living organisms. Moreover, higher plants, like Vicia faba (broad bean) are ecologically relevant to assess soils and soil materials quality. This document has been prepared by Technical Committee ISO/TC 190 "Soil quality", the secretariat of which is held by NEN (Netherlands). The body responsible for this standard is NA 119-01-02-04 UA "Biologische Verfahren" ("Biological methods") at DIN.