Revealing the Structural and Chemical Properties of Copper-based Nanoparticles Released from Copper Treated Wood-Dataset

Copper-based preservatives consisting of micronized and nanoscale copper particles have been widely used in applications for wood protection. The presence of micronized/nanoscale particles and soluble aqueous copper in copper-treated wood has raised questions regarding the forms of released particles and the potential hazards of exposure during the use of these products. However, the lack of a comprehensive understanding of the chemistry of these Cu species is limiting the future investigation of the toxicity of these materials and their potential health impact on workers. In this work, we used a combination of scanning transmission electron microscope (STEM) and electron energy loss spectroscopy (EELS) to analyze the particles released during the sanding/sawing of copper-treated lumber. We have demonstrated using EELS Cu L2,3 edges with comparative reference spectra to determine the Cu species. Three types of species, including basic copper carbonate (BCC), Cu(0), and Cu(II)-Wood complex, were identified in released wood dust particles. The unbound copper particles also exist as a form of BCC or reduced Cu(0). The morphologies and chemical states of emitted copper particles indicate the potential chemical transformation due to copper-wood interactions.