Researchers tested the Prevention through Design (PtD) approach by examining the transition from laboratory-scale to pilot-scale production of Few-Layer Graphene (FLG). Based on PtD principles, they recommended reducing worker exposure to FLG during pilot-scale production through measures like using closed systems, local exhaust ventilation, and semi-automatic storage systems.  The use of PtD in this study provides valuable insights on safety measures during scale up of nanomaterial production in similar settings. 

NanoKey’s insights to reduce worker exposure to Few-Layer Graphene

Reducing worker exposure to Few Layer Graphene (FLG) during pilot-scale production can be achieved by following the principles of Prevention through Design (PtD). This was the conclusion reached by researchers from the Italian NanoKey project, who tested the PtD approach on a real-world example:  the transition from the production of FLG in research and development laboratories to production in pilot plants.

Prevention through Design (PtD) for improving worker protection

Prevention through Design (PtD) is a US proactive approach for keeping workers safe in the workplace. It encourages companies to incorporate safety considerations from the beginning, when designing a new facility, creating a new process, or developing a new product. The primary goal is to identify and eliminate potential hazards before they become an issue. The PtD concept is similar to the EU European Union (European Union )’s Safe by Design idea, which also focuses on integrating safety into the early stages of development. It has a narrower scope than the EU’s Safe and Sustainable by Design (SSbD) concept, that includes human health and safety in general as well as environmental sustainability.

PtD during scale-up of Few Layer Graphene (FLG) production – a real-world example

Researchers Natale and colleagues (2025) studied the safety measures during the transition from laboratory-scale production to pilot-scale production of FLG. The production process included the exfoliation of layered materials, two drying stages, and the storage and cleaning of the finished product. They considered various exposure factors, including the number of particles in the air, the size of those particles, and how much of the material could potentially settle in the lungs of exposed workers. These exposure factors were measured at several locations in the pilot plant, close to the different production process activities and farther away from the activities. 

The transition from the laboratory to pilot-scale production involved a 20-fold increase in production volume. Operational changes included the use of a closed system during synthesis and the first drying stage, as well as the allocation of a separate room for conducting the most intensive powder-handling phases, such as the second drying stage, storage, and cleaning. Unlike the laboratory set-up, workers did not use a glove box for handling the product during storage and cleaning. Personal Protective Equipment (PPE) was used during both production setups, including respiratory protective equipment during the second drying stage, as well as during storage and cleaning. 

Workplace measurements and PtD recommendations

Workplace measurements showed that air concentrations during pilot-scale production were lower in the first drying stage but higher during manual storage and cleaning compared to levels during laboratory-scale production. FLG-like flakes were also found in the air of the exfoliation room, despite it being designated a no-powder zone that did not require the use of respiratory protection equipment. 

To reduce potential exposure, the authors suggested following the PtD principles. They recommended producing and storing FLG either as a liquid suspension or bound to a solid matrix. If this is not possible, they advised isolating dry powder activities within closed systems that have controlled ventilation. They also suggested establishing a semi-automatic storage system for powders. Additionally, they indicated that using local exhaust ventilation can help prevent graphene powder from leaking into powder-free and non-process work areas. 

Reflections by RIVM

PtD promotes the implementation of preventive measures to minimise workplace exposure to substances, especially when their hazardous properties are not well known. This is particularly relevant for substances like FLG, which have uncertain health effects and lack established safe exposure levels. PtD aligns broadly with the Dutch Working Conditions Act (art. 3.1b, Arbowet), as both follow the “hierarchy of controls” principle. This principle advocates for using design solutions to address hazards rather than relying solely on safety procedures or PPE. In line with this principle, the Dutch Guide to safe use of nanomaterials and products proposes a list of measures for reducing exposure in order of priority. 

The PtD process applied in this study provides valuable insights for scaling up nanomaterial production in similar settings. Effective control of FLG exposure levels can be achieved using conventional control measures, provided there is a clear understanding of how different parts of the process impact exposure. This understanding enables the identification of the most effective risk mitigation measures tailored to specific workplace conditions. As recommended by the authors, it is essential to conduct follow-up exposure measurements and, if possible, biomonitoring of exposed workers to assess the effectiveness of the implemented control measures.