Ethyl Chloride can be used to numb the skin before a piercing. It cools the skin down so you will not feel the pain when the skin is pierced. Just spray it on the skin from approximately 30 cm away. When the skin turns white it is ready to be pierced. Stop applying it when the skin has turned white, because this can cause the skin to freeze. For external use only and not to be used near the eyes, ears, nasal passage or genitals.