Powder, Foundation, Blush, Shadows
We never lend mascara, brushes or shades because transfer of microbial flora from one person to another can lead to serious bacterial or viral conjunctivitis, conditions requiring treatment.
Sponges increase greasyness, adding acne.
While the presence of debris can trigger an allergic reaction. Even if a skin looks clean, it does not mean it does not seem to exist.
The transfer of microbial load can trigger a local infection. So it undermines exactly the same danger as if you see a face full of acne. Therefore, proper cleaning and disinfection must be carried out before each use.