In a study published in the Royal Society of Chemistry journal Nanoscale,https://pubs.rsc.org/en/content/articlelanding/2019/nr/c9nr06815e#!div Abstract Spanish and Italian researchers provided a comprehensive and relevant study on the potential of topically applied graphene for irritating the skin.
While graphene producers have heralded this study https://www.graphenea.com/blogs/graphene-news/graphene-not-irritant-to-skin-study-shows as a clear indication that graphene materials do not irritate the skin, it is only one brick in a much larger wall that is still in the very early stages of being built around understanding the potential health risks of graphene exposure, and its safe use, according to Andrew Maynard, https://isearch.asu.edu/profile/2670673 a professor at Arizona State University and an expert on the environmental and health impact of nanomaterials.
Maynard recognizes that the results are significant in that they indicate that there is greater potential for skin harm to occur from the surfactants that some graphene materials are held in, or contain residues of, than from the graphene itself.
“However, while the paper makes an important addition to what is known about the potential impacts or otherwise of skin exposures to graphene, more work is needed to clearly establish how the skin responds to different types and preparations of graphene, and safe limits of graphene skin exposure with regard to irritation,” says Maynard.
Maynard emphasizes that care needs to be taken in comparing skin vs inhalation toxicity/risk/impacts.“Both the exposure mechanisms, the biological barriers and routes, the toxic mechanisms, and the impacts of the outcomes, differ - especially where the end point is irritation rather than other end points,” says Maynard.
While the available exposure area of the skin can make it quite serious if it is exposed to enough material, localized irritation is unlikely to be directly comparable to adverse effects from inhalation, simply because the lungs are vital organs that are highly sensitive to damage. This is true even in instances when the material is able to penetrate through the skin and reach other parts of the body.
Because of the differences between the skin and the lungs, it is dangerous to draw direct comparisons between skin exposure and lung inhalation. Maynard says it more appropriate to consider each system on its own merits and vulnerabilities in terms of exposure and response.
The key formula in understanding the risk of any material is this: risk = hazard (toxicity) x exposure. If a highly toxic material is totally inaccessible, it does not pose a large risk. While a relatively more benign material that is more accessible can pose a larger risk.
While this research brings in the element of skin irritation to discussions of the risk of graphene, there remains a paucity of data, especially when it comes dermal toxicity, despite this most recent research, according to Maynard.
“Like many materials, indications of hazard and risk are highly dependent on many different factors, including the specific material type (including synthesis route and any matrix it is in), exposure route, dose, organs and systems potentially impacted etc.,” says Maynard.“This latest research is the most comprehensive of recent reviews, and indicates that it’s complicated. There is evidence that some forms of graphene are hazardous under certain conditions and scenarios, but the links between hazard are risk (and these links are still vital to assessing risk) remain elusive.”
Maynard agrees with the researchers that because skin exposure is likely to be an issue during production or the use of graphene-based products designed for skin contact, it is important to understand the potential health impacts so they can be avoided.
Maynard adds: “The workplace, even if there’s a hint of possible harm from skin exposure, exposure control is possible by using routine barriers such as gloves, making the possibility of irritation less concerning if good work practices are followed.”