Storage and Handling of Breast Milk

Storage and handling of breast milk

Wash your hands before expressing or handling breast milk. 


  • It's best to store breast milk in glass or BPA-free hard plastic bottles. The breast milk loses fewer antibodies when you put it in glass bottles to freeze it.
  • For healthy term infants, wash containers in hot soapy water, rinse in warmwater and leave to air dry. Then store them in a clean, covered container.
    • If soap is not available, place items in a pot, cover in water and bring to a boil for 5 minutes.
  • Disposable plastic bottle liners are not made for long-term storage of breast milk

    • Individually sterilized breast milk freezer bags are made to store breast milk for freezing.
    • Breast milk tends to lose some of its immune properties when stored in plastic bags. This should not be a problem for a healthy baby who is only getting breast milk that has been frozen occasionally.

Fresh breast milk

  • You can keep it at room temperature (20°C) for up to 6 hours.
  • You can keep it in the fridge for up to 5 days for healthy full term babies. Place breast milk at back of fridge where it is coldest.
  • You can add freshly expressed breast milk that you have let cool first, to the same bottle as breast milk expressed on the same day.

For a premature or hospitalized baby

  • Use a sterile container.
  • Refrigerate milk immediately after pumping.
  • You can keep milk in the fridge for up to 48 hours.

Freezing breast milk

  • You can freeze breast milk in small amounts (2 to 4 oz/ 60 to 120 ml) and label it with the date.
  • Store in back of freezer on top shelf in separate refrigerator freezer for 3 to 6 months (bottom shelf warms during defrost cycle).
  • You can keep up to 6 to 12 months in a deep freezer.

Thawing breast milk

  • Check the date on the container to make sure that it has not expired. Use the container with the earliest date first.
  • Breast milk is best thawed under warm running water. You can also warm the container of breast milk in a bath of warm water.
  • You can thaw frozen breast milk in the refrigerator. You must use it within 24 hours of taking it out of the freezer. Do not thaw breast milk at room temperature.
  • Frozen breast milk separates into low and high fat layers. Gently swirl bottle to mix.
  • Do not heat on the stove or in a microwave. There is a risk of mouth burns as well as loss of immune properties. A bottle heated in a microwave may feel cool but can contain pockets of very hot liquid.

Once frozen breast milk has come to room temperature, you must you use it right away or throw it out.

Do you have more questions about parenting?

  • Connect with a registered nurse from Health811 for free, secure, and confidential health advice. Service is available 24/7 in English and French, with translation support also offered in other languages. Call 8-1-1 or visit
  • Connect with a Community Navigator from 2-1-1 for information about community programs and resources across Eastern Ontario. Helpline service is available 24/7 and in many different languages. Call 2-1-1 or visit
  • Connect with other parents on the Parenting in Ottawa Facebook page.
  • There are a variety of services to make it easier for your child to grow up healthy in Ottawa.
  • You can update your child's immunization record using either the CANImmunize App or the Immunization Connect Ontario (ICON) Tool
  • If you have received a message from Ottawa Public Health such as a letter or a call regarding immunization, an infectious disease, or infection control lapse, please call 613-580-6744 and listen to the menu options carefully.
September 2019

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