Glitter/Airbrush Tattoo and simple Facepaint design usually take around 2/5 of minutes depending on the design. More complex Facepaint design could much more. A full Bodypaint usually don't take more then 6/7 hours. It can eventually take from 3 to 6 hours depending on the complexity of the design or if I have an assistant.
Anybody without spefic allergies or skin issues.
I only use the top professional paint brands and I always buy at professional known stores. All these brands are tested for skin safety and are for kids and adults. There are exceptions for anyone with allergies, intollerances and skin problems. Also, I take good and serious care of cleaning and sanitizing all my brushes and colors. For more details see the question below.
Oh, Yes! All my brushes are always cleaned and sanitized with specific products ,also used to sanitize baby care objects, after every session. I also make sure products are correctly dry and correctly stored after the sanitization process.