In 2006-07 NICNAS completed to public comment stage previously drafted hazard assessments of 25 phthalate chemicals, together with a compendium summarising toxicological and use information on the 25 chemicals. The compendium highlights data gaps, comments on toxicological and molecular structural similarities and differences between the chemicals and for chemicals with little data extrapolates likely toxicological effects based on structurally similar phthalates.