As the information pertaining to nanomaterial toxicology is currently inadequate, we’ve used to
perform hazard ranking of the selected nanomaterials (NMs) in the recent years by extrapolating it
according to the information form their bulk counterparts, and formulated it by considering the hazard
levels of these nanomaterials as being one magnitude higher than those of the bulk counterparts.
However, it’s still necessary to provide more toxicology and chemical hazard information to verify the
feasibility of such strategy. Currently, zebrafish has been recommended by ISO as the NMs toxicity
screening animal model, and hopefully we may obtain more toxicology data to sufficiently serve as
the basis of NMs-specific hazard banding. In our studies, we chose nano zinc oxides, which have been
widely applied in daily life and display toxic potential, as the model nanomaterial, and compared its
toxicity with that of the counterpart bulk powers by using zebrafish embryos and larvae respectively.
We attempted to make our results applicable for NMs-specific hazard ranking and control banding. Our
results showed that the LC50 (50% lethal concentration) and EC50 (50% effective concentration) values
of nano zinc oxides are comparatively lower than those of bulk zinc oxides. According to the acute
aquatic toxicity classification criteria, we recommended nano zinc oxides as "hazard ranking one" and bulk zinc oxides as " hazard ranking two". In this regard, this suggest that the NMs have to be assigned
to a higher hazard band, in terms of acute toxicity, as compared to the bulk powder counterparts. We
preliminarily confirmed the feasibility of using toxicology information of bulk zinc oxides to carry out
hazard banding of nano zinc oxides and ranking them by considering them as at least one magnitude
higher. As a result, nano zinc oxides must be subjected to the management plan.