Because it is such a new material and toxicological research is only just catching up to itâ€s industrial use, there are no occupational exposure limits created for graphene. Immediate effects from short term exposure suggest it may be harmful to humans if inhaled. There is evidence that it may cause respiratory tract irritation. Preliminary research on animals shows graphene has the potential to harm the lungs, according to Health Canada. Although these are early days, there are no recorded observations of skin irritation or skin sensitization, graphene may cause eye irritation. Graphene may be harmful if swallowed and cause internal damage. There are currently no known chronic effects from long-term exposure or reports of carcinogenicity in animals. No indication of reproductive and developmental toxicity has been observed either.