Wear gloves when zesting chili peppers to prevent skin irritation from capsaicin, the compound that makes them spicy. Avoid touching your face, especially your eyes, while handling the peppers.
Chili peppers contain capsaicin, an irritant that can cause a burning sensation on the skin and in the eyes. Zesting chili peppers releases this compound, making it more likely to come into contact with your skin. Wearing gloves, preferably disposable nitrile or latex gloves, creates a barrier between your skin and the capsaicin. After handling the peppers, even with gloves, wash your hands thoroughly with soap and water. It's also crucial to avoid touching your face, particularly your eyes, as even trace amounts of capsaicin can cause significant discomfort. If you do get capsaicin in your eyes, flush them immediately with cool water for several minutes.
If you don't have gloves, you can try rubbing a small amount of vegetable oil on your hands before handling the chili peppers. The oil can help create a barrier, but it's not as effective as gloves. Be sure to wash your hands thoroughly afterward, even if you use oil.