Characterization of water‑based paints containing titanium dioxide or carbon black as manufactured nanomaterials before and after atomization

The study aims to bring more knowledge about risk assessments of paint aerosol exposure to the human body. Raw manufactured nanomaterials (MNMs), either titanium dioxide or carbon black, were introduced into water-based paint formations. The evaluation of the acute and subacute potential toxicity of these samples in a whole-body (mice) exposure model was performed. Inhalation aspects are especially regarded and description of the results obtained from each characterization stage of paint materials (raw MNMs, suspensions of MNMs, paint containing them and paint aerosol produced) is reported. Several techniques such as X-ray photoelectron spectroscopy, centrifugal liquid sedimentation, transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and electrical low impactor were used to this objective. The modification of physicochemical properties of MNMs, incorporated into paint formulation before and after atomization process, was shown. The evidence of MNMs agglomerates inside micro-sized paint droplets in the overspray was highlighted and findings revealed that MNMs are strongly embedded into the paint matrix. This behavior indicates that minor or no potential toxicity exerted by MNMs in this type of complex products may be observed.