It is highly unlikely that anyone would be able to inhale or suck ink through one of our Blendy airbrushes. It would take a huge amount of force to suck the ink through the small hole and back up the airbrush. Due to the shape of the airbrush, going from the more round mouthpiece to the small hole across the nib concentrates the air to vaporize and spray the ink. So the other way you are pulling a tiny amount of air through to a large area, reducing the flow.
This has been tested in the office and we were unable to even get color on the inside of the tube. The pens are tested to the highest safety standards and are non-toxic and non-harmful