The OvuFirst Sensor is designed with medical grade materials that prevent growth of bacteria. The OvuFirst Sensor should be cleaned on first use, and before or after each use by washing it with unscented and fragrance free soap in warm water. DO NOT clean the OvuCore Sensor in disinfectants or alcohol, or with antibacterial or disinfectant wipes, or 'intimate wash' soap, or with soaps that contain additives and/ or essential oils.