In order to qualify for a license, a gym teacher must have a minimum of a bachelor's degree and pass competency examinations covering both general education and topics pertaining to their area of specialty. After a teacher is licensed, they must also meet continuing education requirements set by their state.
Mistake #3: Keeping mixed formula out too long. Formula that is sitting out at room temperature must be thrown away after 1 hour. If it is in the refrigerator, pre-mixed formula (also called ready-to-feed formula) that is opened must be thrown out after 48 hours. Formula that you mixed must be thrown out after 24 hours. Mistake #4: Re-using leftover formula.
Multidose vials have a limit on how long they can be stored after being opened or punctured; typically that limit is around 28 days. Your multidose vial may have an expiration date on the label, but that does not take into consideration the date the vial is first used, which is when the 28-day rule takes effect.