Researchers say that graphene is one of the most interesting and versatile substances they have ever seen. Its potential applications could revolutionize many sectors of the economy. But are products containing graphene safe? Specifically, are they safe for humans and the environment?
EMPA researchers, along with several other European colleagues, investigated this question in a comprehensive review. EMPA stands for Eidgenössische Materialprüfungs- und Forschungsanstalt (Swiss Federal Laboratories for Materials Science and Technology).
A miracle material – but is graphene safe?
Graphene is the thinnest, lightest, and strongest material in the world. It is also the world’s best conductor of both heat and electricity. It is a single layer of pure carbons in a honeycomb, hexagonal lattice arrangement.
Many scientists regard it as the miracle material of tomorrow. Not only is it strong, but also flexible and transparent. It can assume different electrical properties.
All these qualities make graphene extremely interesting for countless potential applications. The ‘Graphene Flagship,’ Europe’s largest research initiative to date, is dedicated to this material.
However, in spite of all the excitement, we must take into account the potential downsides of the material early on. Historically, have tended to leave things until it is too late.
We loved asbestos, for example, in the early twentieth century because of its amazing fire-retardant properties. We used it to manufacture thousands of different products. In 1970, however, the authorities classified asbestos fibers as carcinogenic.
Graphene Flagship question: “Is graphene safe?”
An important question that the Graphene Flagship must answer is “Is graphene safe?.” Researchers have carried out several studies within the framework of the Flagship. EMPA researchers investigated how graphene oxide might affect the placental barrier, lungs, and gastrointestinal tract.
A large team of European researchers carried out a comprehensive study on the safety of graphene. They wrote about their study and findings in the journal ACS NANO (citation below).
The authors provided an overview of when parts of graphene-based materials can enter the human body or the environment. Specifically, during the material’s lifecycle, i.e., production, use, aging, disposal, or the recycling process.
Most of the studies that they evaluated focused on the question: “Is graphene safe for humans?” In other words, how graphene-based materials interact with the human body. These studies included different ways the materials might enter the body. The might enter through, for example, skin contact, inhalation, or ingestion.
They also looked at studies that focused on graphene distribution and interaction with major organs such as the CNS, lungs, reproductive system, cardiovascular system, skin, lungs, and immune system. CNS stands for the central nervous system.
“Is graphene safe?” Study findings vary
Not all the studies’ findings matched, the authors noted. However, that was not necessarily because the quality of some studies was poor.
Peter Wick, head of EMPA’s Particles-Biology Interactions Lab, said:
“The challenge is that not all graphene is the same. Graphene-based materials can consist of one or more layers, the width and length of the layer can vary, and the ratio of carbon to oxygen atoms can also differ.”
Different combinations of these three parameters often result in completely different material properties. Also, their effects on the environment and humans vary significantly. Therefore, it is impossible to make simple, generally valid statements.
Dr. Wick said:
“Our goal is therefore to create a detailed model for a relationship between structure and certain properties.”
In an article on EMPA’s website, Karin Weinmann wrote:
“Careful characterization of the materials studied is therefore central. In the future, self-learning algorithms could help to generate a model from the data in order to predict the biological effects of a certain graphene structure.
There are still gaps in our knowledge
Regarding their answer to the question: “Is graphene safe?” Dr. Wick explained:
“We see ourselves here as a kind of launch helper for determining the safety of graphene-based materials and products. Although there are more and more studies and thus indications of how graphene-based materials affect living systems, there are still gaps in our knowledge.”
“These gaps need to be filled before we can make a clear prediction about how a graphene-based material with certain properties will affect biological systems.”
“Safety Assessment of Graphene-Based Materials: Focus on Human Health and the Environment,” Bengt Fadeel, Cyrill Bussy, Sonia Merino, Ester Vázquez, Emmanuel Flahaut, Florence Mouchet, Lauris Evariste, Laury Gauthier, Antti J. Koivisto, Ulla Vogel, Cristina Martín, Lucia G. Delogu, Tina Buerki-Thurnherr, Peter Wick, Didier Beloin-Saint-Pierre, Roland Hischier, Marco Pelin, Fabio Candotto Carniel, Mauro Tretiach, Fabrizia Cesca, Fabio Benfenati, Denis Scaini, Laura Ballerini, Kostas Kostarelos, Maurizio Prato, and Alberto Bianco. ACS NANO 2018, 12 (11), pp 10582–10620. DOI: 10.1021/acsnano.8b04758.