Occupational exposure to nanomaterials: Assessing the potential for cutaneous exposure to metal oxide nanoparticles in a semiconductor facility

This study evaluated the potential for cutaneous exposures to engineered nanometal oxides from workplace surfaces in a semiconductor research and development facility. Exposure assessment methodology captured engineered nanomaterials (ENMs) from work surfaces accessible for worker contact via the skin that were associated with chemical mechanical planarization (CMP), a polishing process utilized in semiconductor fabrication. A microvacuum approach was used to collect surface samples for morphological analysis via transmission electron microscopy (TEM) and scanning electron microscopy (SEM), both with energy-dispersive X-ray spectroscopy (EDS) for compositional analysis. Eleven surface samples were collected along the CMP lifecycle: 1 from the cleanroom (“fab”) where wafer fabrication takes place, 4 from the subfab where bulk chemical delivery systems are located, and 6 from the wastewater treatment (WWT) area where CMP wastewater is treated and discharged. Engineered nanomaterials of interest (Si, Al, Ce) were found from all areas of collection, existing as particles or agglomerates (>100 nm). Results support the findings of prior research and indicate that nanomaterials utilized or generated by CMP are found on work surfaces and may be accessible for cutaneous exposure by workers in semiconductor facilities. In order to minimize and/or prevent cutaneous exposures for workers who use or handle ENMs in this industry, prudent preventive work practices should be followed, including use of personal protective equipment, hazard communication, and engineering and administrative controls.