A large Ames test dataset can be used to create HNC data with a 95% confidence interval. The HNC ranges have been used to analyse the concurrent strains dose-response data and to identify Ames test data in the Vitic database that may require investigation. Used alongside other acceptance criteria such as calculating the fold-increase in revertants, a review of specific records will aid users in their expert review and clearly show the multiple criteria used to review Ames test results, establishing whether a substance is mutagenic.