Initial sense-testing suggests that more than 75% of nano materials would score at below this threshold range (80-100) and thus far the tool agrees with 18 out of 19 authoritative published assessments. There is a difference of opinion about nano silver.
The properties assessed in the tool are: size range, persistence, accessibility, agglomeration, ionic forms and fibre size (where applicable). Responsible manufacturers will have this information as part of their product quality assurance system. Properties such as carcinogenicity, biocidal potential and sensitization are assessed separately as there is no validated nano-specific prediction yet available. As the science develops and becomes more standardized, other validated assessment criteria could be added into the assessment.