Low toxicity of HfO2, SiO2, Al2O3 and CeO2 nanoparticles to the yeast, Saccharomyces cerevisiae

► First cytotoxicity study on common/emerging inorganic oxide nanoparticles to yeast. ► Components in the culture medium promoted nanoparticle aggregation. ► Toxicity tested with/without non-toxic dispersant to address agglomeration issue. ► SiO2, Al2O3 and HfO2 nanoparticles were not inhibitory to O2 uptake by yeast. ► Only dispersed CeO2 caused moderate inhibition of O2 uptake (47% at 1000 mg/L). ► Dispersed nano-sized SiO2 and Al2O3 caused some cell membrane damage to the yeast.