Ss14-01 the Assessment of Occupational Exposure to Nanomaterials

Introduction Over the past decades, nanomaterials, materials with at least one dimension smaller than 100 nm, have become commonplace in modern, multifunctional products. Assessing the exposure to these Nano-Objects and their Agglomerates and Aggregates (NOAA) is challenging but necessary to properly assess and manage their risks. Materials and Methods A review of factors influencing exposure and dose estimates for NOAA. Results Occupational exposure to NOAA is often in the form of aerosols. These may be individual units of the nanomaterial, but more commonly are agglomerates and aggregates. Exposure to solids and liquids containing nanomaterials is also frequent. Release is controlled by the dustiness of the nanomaterial, which is influenced by its dimensions, structure and surface properties. When embedded in a matrix, the interplay of structure and matrix properties with the type(s) of processes and activities is key to the release. Once in the air, depending on their chemistry, nanomaterials may agglomerate and aggregate with other aerosols, chemically transform, or adsorb gaseous molecules to their surface. Conclusions Workers’ exposure to nanomaterial is not necessarily to the initial “pure” NOAA. Risk assessment and management must take this into account. Protection strategies against nanomaterial exposure best focus on release. It is necessary to understand the type of nanomaterial, whether and how it is embedded in a matrix, and what processes and activities are taking place. Where release control is not sufficient, it is important to understand potential transformations during production, release and transfer so that the type(s) and mixtures of material(s) to which workers are exposed are properly understood.