On December 20, 2022, the European Union (EU) Observatory for Nanomaterials (EUON) published a Nanopinion entitled “Controlling Exposure to Nanomaterials” by Dr Araceli Sánchez, Spanish Institute of Health and Safety (INSST). Sánchez notes that over the last 15 years, scientists have paid attention to the development of new instruments capable of measuring personal exposure to nanosize particles, and new frameworks, methodologies, and standards to assess and control exposure to engineered nanomaterials in the workplace have been published. According to Sánchez, since 2007, some institutions, such as the United Kingdom’s (UK) British Standards Institution (BSI), the U.S. National Institute for Occupational Safety and Health (NIOSH), the German Institute of Occupational Safety and Health (IFA), and the Dutch government started to recommend pragmatic “benchmark exposure levels” to control workplace exposures to nanomaterials. Sánchez states that this “undoubtedly” was a necessary measure to minimize exposure. The benchmark values were developed following different approaches (Mihalache et al. 2016), however, and “with the exception of those proposed by NIOSH,” do not represent health-based occupational exposure limits (OEL). Health-based inhalation OELs are time-weighted average (typically eight-hour) air concentrations believed to represent a safe level of exposure for most workers over their working lifetime. Benchmark values are cautious levels to prevent exposure, but do not represent safe levels to which workers can be exposed without developing adverse health effects. Sánchez states that some advances on this front have been published recently, such as Visser et al. (2022), which provides recommendations from an expert panel to establish health-based nano reference values differentiating six groups of engineered nanomaterials.