Evaluating occupational exposures to the graphene family of nanomaterials: Implications for worker safety and health

Graphene, a two-dimensional carbon-based nanomaterial, has garnered significant attention due to its exceptional physical and chemical properties, leading to its widespread application in various industries. However, the increasing utilization of this class of materials, also referred to as the graphene family of nanomaterials (GFNs), raises potential concerns regarding occupational exposures and health risks for workers. This study aimed to evaluate occupational exposures to GFNs across 11 primary and secondary manufacturing facilities operating in the U.S. A total of 44 workers participated in the study, with paired personal air samples collected for elemental carbon (EC) analysis at both the respirable and inhalable aerosol size fractions. The results revealed exposures with respirable EC concentrations ranging from <0.01 to 1825.23 µg/m³ with a geometric mean (GM) of 2.01 µg/m³ and inhalable concentrations from 0.01 to 6327.10 µg/m³ with a GM of 12.63 µg/m³. Notably, 38% of respirable samples exceeded a suggested occupational exposure band (OEB) of <10 µg/m³ established from a recent publication for GFNs, while 53% of inhalable samples exceeded the OEB. Primary manufacturing facilities that produce GFNs generally exhibited higher inhalable exposure levels compared to secondary manufacturers, likely due to the handling of larger quantities of dry powdered materials. Additionally, the use of engineering controls and personal protective equipment varied widely among facilities, impacting exposure levels. This study represents a crucial step in understanding any potential occupational risks associated with U.S. GFN exposures.