The importance of quality material for body painting, face painting or belly painting is paramount, too many people use unsuitable products.
This is not without risk, so much so that the brand Crayola (manufacturer of non-toxic colored pencils) made an official statement on the fact that these pencils are not suitable for body painting. Indeed nontoxic does not mean that it can be used on the skin, like makeup or a special painting of Body painting, without risk.
This is the official version of the Crayola brand of colored pencils:
As a manufacturer of children's products, product safety is one of Crayola's top priorities. Even if our products are tested and conform to the standards, it is strongly recommended not to use them as lipsticks, eyeliner or any other makeup product. They have not been created, tested and approved for this purpose.
Their products (very good for children's drawing) are indeed safe if a child (or any other person) puts on his fingers or eat a piece but they are not designed to actually paint the skin in prolonged application, particularly sensitive areas such as eyes or lips.
You must use special paints (cream or blush, etc.) that are suitable for this purpose. Do not trust any tutorials that use Crayola crayons (or other inappropriate materials). These are made by incompetent people (see dangerous) who should disappear from the world of body painting.