Graphene – Magical innovation with a deadly bite
Disease Aware Issue 7
Graphene has been termed a ‘miracle material’ and is very much at the forefront of developing nanotechnology.
It was first produced at the University of Manchester by Physicists Andre Geim and Konstantin Novoselov, who announced that a single sheet of 1m², weighing less than a cat’s whisker, could support the weight of a 4kg cat. They were awarded the Nobel Prize in Physics in 2010.
What is graphene?
Graphene is a pure carbon where the atoms are densely packed together into a chicken wire shape. It is one atom thick. It is 300 times stronger than steel and very light. It is harder than diamond. It is efficient at conducting heat and electricity.
The material has led to remarkable innovations and is used for lubricants, paints and steel products. There is scope for development in a wide range of fields.
The Advanced Institute of Science and Technology in South Korea has created multi-layered composites. One development in adding 0.00004% by weight of graphene to nickel resulted in the material being 180 times stronger.
The applications for stronger and lighter cars and aircraft are obvious. There has also been much mention of innovations in touch screen smart phones and superfast broadband connections. Perhaps one day every smart phone will contain graphene.
The interest in graphene promotes investment into graphite mines, such as the Loharano mine in southern Madagascar, which produces top quality high-value flakes of graphene.
Research and development
In Manchester a £61 million National Graphene Institute has been established. It hosted a Graphene Week in June 2015 and is committed to developing innovative and safe applications.
Amid all the excitement surrounding graphene, some commentators have put forward warnings that this miracle material has similarities with asbestos, which was previously known as a ‘magic substance’.
A 2013 paper from Brown University reviewed how jagged graphene could slice into cell membranes and postulated that graphene sheets “could be big trouble for human cells”.
This research concluded that sharp corners of jagged protrusions along the edges of graphene sheets can pierce cell membranes in human lungs, skin and immune cells. After the cell is pierced, the entire sheet can be pulled into the cell, which can result in cellular disruption. Graphene could be dangerous to both humans and the environment.
As with any nano material, the fact that the composite material is so small creates the potential that it can be inhaled unintentionally, and it is difficult to control its impact on the environment.
Another study from the University of California examined how graphene oxide particles became less stable in groundwater sources and would settle out, or be removed in sub-surface environments. However, in lakes or rivers the particles were more stable and stayed under the surface.
The co-author Jacob D Lanphere said, “We just don’t know much about what happens when these engineered nanomaterials get into the ground or water and we have to be proactive to promote sustainable applications in the future”.
A study by Cyrill Bussy in 2013 on ‘Safety Considerations’ concluded that in view of varied applications of graphene, generalisations about the toxicity as a whole will be “inaccurate, possibly misleading and should be avoided”. Indeed, it may be that graphene is no more harmful as one commentator suggests “as a school child licking their pencil”.
So, how should we deal with graphene presently, whilst its application and use becomes more wide-spread?
At present, graphene is available with the Material Safety Data Sheet governing the industrial use of graphene. The ACS Material Single Layer Graphene Data Sheet confirms that the substance is not listed as a hazardous material under US Federal Regulations.
It does highlight graphene as a potential irritant of skin and eyes and it is potentially hazardous to breathe and ingest. The potential carcinogenic effects are marked “Not available”. Whilst there is no suggestion of any carcinogenic properties or other toxicity, there is no confirmation that it is safe.
The Data Sheet also states that graphene may be toxic to the upper respiratory tract. The substance may be toxic to the cardiovascular system. It warns that repeated or prolonged exposure can produce targeted organ damage.
It provides advice on safe handling – that there should be good ventilation and “personnel should take measures to avoid breathing dust created…and wear suitable protective clothing to prevent skin and eye contact”.
The “special remarks on other toxic effects on humans” point to nuisance dust causing skin and eye irritation. In high concentrations over prolonged periods it can cause pneumoconiosis and exacerbate pre-existing respiratory problems like emphysema. Crucially, it states, “The toxicology of graphene has not been fully investigated”.
Whether graphene over time proves to be a magic material with no downside or we see a repeat of the long-running issues arising from asbestos use, remains to be seen. As with many areas of disease litigation, it is often many years and perhaps decades before any claims arise, and it is important for employers and producers to keep abreast of current knowledge.