"Safe" is a loaded term.
Tamiya acylics are made from liquid acrylic resins and pigments, and one of the primary solvents appears to be alcohol, as Bill said. They pose little hazard when hand painting.
Anything in aerosol form, say from an airbrush, is more readily absorbed through the respiratory system. While acrylic paints are generally less hazardous than enamels or lacquers when in aerosol form, that does not mean they are completely harmless. A spray booth is highly recommended for spray application of any coating. In the absence of a spray booth, I'd use an organic vapor respirator, and make sure that the room air is exhausted outside the house, or do my spray painting outside.
DO NOT USE A DUST MASK. A dust mask only protects you from particulates, not from vapors. It also has the potential to concentrate the vapors breathed by the wearer.