Before first use: 1. Use clean hands and clean surfaces when handling. 2. Place nipple in an open container of boiling water for five minutes. If boiled longer, the nipple can deteriorate. 3. Be sure the nipple hole is clean. After first use: Nipples may be cleaned in a dishwasher-top rack only. Water temperature should not exceed 140°F (60°C). Before each use: Pull on the nipple to make sure it does not tear. Replace the nipple if it shows any signs of wear - such as cracking or change of shape. Small pieces can accidently be inhaled and cause serious injury. Be sure to contact your physician should you have any feeding problems or questions.