Edinburgh Napier University

  Nanoscale copper phthalocyanine (n-CuPc) is a pigment widely used in paints to enhance automobile coatings and to make colors transparent and more appealing to users. Despite the benefits, n-CuPc can potentially be released into the environment and pose risks in occupational settings. Assessing the toxicity of released n-CuPc-containing fragments is thus important for the acceptance of n-CuPc products. This paper presents the first combined study addressing both the release of n-CuPc-containing fragments from commercial coatings in realistic occupational situations and the hazard of the released fragments using a macrophage model.

Sanding was used to produce fragments from automobile coatings with n-CuPc as well as from a reference coating with the same matrix composition but without n-CuPc. Size distribution and agglomeration of these fragments in Rosewell Park Memorial Institute (RPMI) cell culture medium was studied before conducting a battery of cytotoxicity experiments. Cell viability and reactive oxygen species (ROS) production were conducted and particle localization within cells was analyzed.

The results show similar size and number distribution of fragments when comparing the reference and n-CuPc fragments. The n-CuPc fragments showed higher agglomeration in RPMI than pristine n-CuPc. We found that toxicity of the n-CuPc fragments and reference materials was similar (EC50 Frag n-CuPc = 242.9 μg ml− 1; EC50 Frag Refer = 241.6 μg ml− 1) and below the toxicity of pristine n-CuPc (EC50 n-CuPc = 151.1 μg ml− 1). The results demonstrated that embedding n-CuPc in matrix used in automobile coatings reduced the toxicity and release when n-CuPc is used in paints. Our finding can be used to support design of n-CuPc-enabled products used in automobile applications.