Zinc oxide nanoparticles in modern sunscreens: An analysis of potential exposure and hazard

Abstract

Sunscreens containing metal oxide nanoparticles appear transparent on the skin and provide excellent protection against sunburn caused by UV radiation. While it is likely that nanoparticles remain on the surface of the skin of healthy adult humans, and thus are considered safe for use in sunscreens, there has been no comprehensive assessment of the impact on human health from exposure to the metal oxide nanoparticles destined for use in sunscreens, either in the workplace during the manufacturing process, in long-term use across a range of skin conditions, or upon release into the broader environment, either accidentally or consequent of normal sunscreen use. In this review, we focus on zinc oxide nanoparticles destined for use in modern sunscreens, and discuss the potential for human exposure and the health hazard at each stage of their manufacture and use. We highlight where there is a need for further research.

Keywords::

• Nanotoxicology
• nanoparticle
• zinc oxide
• sunscreen

Acknowledgements

The authors gratefully acknowledge Brendan Carney (Department of Infrastructure, Transport, Regional Development & Local Government Australia) for providing advice regarding the possible OH&S issues surrounding the transport of ZnO nanoparticles in Australia. We would also like to thank Glenn McLeod for preparing the diagrams used in this manuscript, and Phil Casey (CSIRO) for his critical reading, suggestions and comments.

Declaration of interest: Work on this manuscript was supported by the Nanosafety Theme in the CSIRO Future Manufacturing Flagship, which receives its funding from the Australian Government. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.