Paint has the potential to release microplastics, nanoplastics, inorganic nanoparticles, and hybrid materials

Abstract Background When we paint our houses or offices, we might paint plastic, because most paints are generally formulated with polymer binders. After drying and curing, the binders fix the colourants on the painted surface as a film of plastic mixture, which is tested herein using Raman imaging to analyse and directly visualise the hybrid plastic-colourant (titanium dioxide or TiO 2 nanoparticles). Results For the plastic mixture or hybrid, the co-existence and competition between the Raman signals of plastic and TiO 2 complicate the individual analysis, which should be carefully extracted and separated in order to avoid the weak signal of plastic to be masked by that of TiO 2 . This is particularly important when considering the Raman activity of TiO 2 is much stronger than that of plastic. Plastic is observed to coat the TiO 2 nanoparticle surface, individually or as a bulk to embed the TiO 2 nanoparticles as mixture or hybrid. Once branched, pended, scratched or aged, the paint can also be peeled off from the painted surface, including gyprock, wood and glass, releasing microplastics and nanoplastics (coating onto the individual TiO 2 nanoparticle surface or embedding the TiO 2 nanoparticles, or individually as particles) in potential. Conclusions Our test sends us a warning that we are surrounded by plastic items that might release microplastics and nanoplastics in potential, for which the risk assessment is needed. Overall, Raman imaging is a suitable approach to effectively characterise microplastics and nanoplastics, even from the mixture with the hybrid background and the complicated interference. Graphical Abstract