How to Keep Your Breast Pump Kit Clean: Science Behind the Recommendations

baby bottles upside down drying after being washed

Providing breast milk is one of the best things you can do for your baby’s health and development. Pumping your milk is one way to provide breast milk to your baby. However, germs can grow quickly in breast milk or breast milk residue that remains on pump parts 1,2. Following these steps can keep your breast pump clean and help protect your baby from germs. If your baby was born prematurely or has other health concerns, your baby’s healthcare providers may have more recommendations for pumping breast milk safely.

The steps outlined below are based on the available scientific literature and expert opinion on breast pump hygiene. However, more research is needed to answer some questions about how to best clean breast pump equipment.

Before Each Use

  1. Wash hands. Wash your hands well with soap and water for 20 seconds.
    • Washing hands is the first line of defense against contamination of your breast pump kit and the breast milk itself. Washing with soap and water is preferable to the use of alcohol-based hand sanitizer so as not to introduce alcohol to the breast or breast milk 3. However, when used correctly, hand sanitizer [PDF – 2 pages] should not pose a risk to your breast milk and can be used if soap and water are not readily available.
  2. Assemble. Assemble clean pump kit.
    • Inspect whether the pump kit or tubing has become moldy or soiled during storage. If your tubing is moldy, discard and replace immediately. 3,4,5
    • A 1979 outbreak of Klebsiella bacteremia in a newborn intensive care unit was linked to contaminated breast pump tubing.6
  3. Clean if using a shared pump. Clean pump dials, power switch, and countertop with disinfectant wipes.
    • The outer surfaces of shared pumps can have unsafe bacteria that may carry into the pumped breast milk. 6

After Every Use

  1. Store milk safely. Cap milk collection bottle or seal milk collection bag, label with date and time, and immediately place in a refrigerator, freezer, or cooler bag with ice packs.
    • If milk collection container will be stored at a hospital or childcare facility, add name to the label.
  2. Clean pumping area. Especially if using a shared pump, clean the dials, power switch, and countertop with disinfectant wipes.
    • The outer surfaces of shared pumps can have unsafe bacteria that can get into pumped breast milk. 6
  3. Take apart and inspect pump kit. Take apart breast pump tubing and separate all parts that come in contact with breast/breast milk (for example, flanges, valves, membranes, connectors, and milk collection bottles).
  4. Rinse pump kit. Rinse breast pump parts that come into contact with breast/breast milk under running water to remove remaining milk.
  5. Clean pump kit. As soon as possible after pumping, clean pump parts that come into contact with breast/breast milk in one of the following ways.
    • Clean by hand.
      1. Use a wash basin. Place pump parts in a clean wash basin used only for washing infant feeding equipment. Do not place pump parts directly in the sink, because germs in sinks or drains could contaminate the pump.
        • Many germs can easily grow in sink drains and spread to other surfaces. Outbreaks in hospitals have been linked to germs from sink drains. 7,8,9,10
      2. Add soap and water. Fill wash basin with hot water and add soap. 11,12
      3. Scrub. Scrub items according to pump kit manufacturer’s guidance. If using a brush, use a clean one that is used only to clean infant feeding items. 11,12
      4. Rinse. Rinse by holding items under running water, or by submerging in fresh water in a separate basin that is used only for cleaning infant feeding items.
      5. Dry. Allow to air-dry thoroughly. Place pump parts, wash basin, and bottle brush on a clean, unused dish towel or paper towel in an area protected from dirt and dust. Do not use a dish towel to rub or pat items dry because doing so may transfer germs to the items.
        • Research in a neonatal intensive care unit setting found Proteus spp. bacteria at the bottom of a milk bottle. The study concluded that breast pump kits should be dried thoroughly to not allow for any water to remain where bacteria can multiply. 13
    • Clean in a dishwasher (if recommended by pump kit manufacturer).
      1. Wash. Place disassembled pump parts in dishwasher. Be sure to place small items into a closed-top basket or mesh laundry bag so they don’t end up in the dishwasher filter. If possible, run the dishwasher using hot water and a heated drying cycle (or sanitizing setting); this can help kill more germs.
      2. Remove from dishwasher. Wash your hands with soap and water before removing and storing cleaned items. If items are not completely dry, place items on a clean unused dish towel or clean paper towel to air-dry thoroughly before storing. Do not use a dish towel to rub or pat items dry because doing so may transfer germs to the items.
        • A systematic review concluded that a number of different methods for cleaning and disinfecting a breast pump kit appear to be acceptable, including thoroughly washing with warm water and soap, using a dishwasher, and boiling 14,15. The authors did conclude that whatever method is used, the most important steps are thoroughly washing with warm water and soap to remove all traces of milk, rinsing to remove the soap, and then thoroughly drying before storing.
  6. Clean wash basin and bottle brush. If you use a wash basin or bottle brush when cleaning your pump parts, rinse them well and allow them to air-dry after each use. Consider washing them every few days, either in a dishwasher with hot water and a heated drying cycle, if they are dishwasher-safe, or by hand with soap and warm water.
  1. Lenati RF, O’Connor DL, Hébert KC, Farber JM, Pagotto FJ. Growth and survival of Enterobacter sakazakii in human breast milk with and without fortifiers as compared to powdered infant formula. Int J Food Microbiol 2008;122:171–9.
  2. Eidelman AI, Szilagyi G. Patterns of bacterial colonization of human milk. Obstetrics and Gynecology 1979; 53:550-2.
  3. Rhodes J. Evidence-based recommendations for breast pumping hygiene. Neonatal Intensive Care 2012; Suppl; 13-15.
  4. Price E, Weaver G, Hoffman P, Jones M, Gilks J, O’Brien V, Ridgway G. Decontamination of breast pump milk collection kits and related items at home and in hospital: guidance from a Joint Working Group of the Healthcare Infection Society and Infection Prevention Society. Journal of Infection Prevention 2016; 17: 53-62.
  5. Donowitz LG, Marsik FJ, Fisher KA, Wenzel RP. Contaminated breast milk: a source of Klebsiella bacteremia in a newborn intensive care unit. Rev Infect Dis 1981; 3: 716-20.
  6. Engur D, Cakmak BC, Turkmen MK, Telli M, Eyigor M, Guzunler M. A milk pump as a source for Acinetobacter baumanii in a neonatal intensive care unit. Breastfeeding Medicine 2014;9:551-4.
  7. Rusin P, Orosz-Coughlin P, Gerba C. Reduction of faecal coliform, coliform, and heterotrophic plate count bacteria in the household kitchen and bathroom by disinfection with hypochlorite cleaners. J Appl Microbiol 1998; 85: 819-28.
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  10. Kotsanas D, Wijesooriya WR, Korman TM, et al. “Down the drain”: carbapenem-resistant bacteria in intensive care unit patients and handwashing sinks. Med J Aust 2013; 198: 267-9.
  11. Ma L, Zhang G, Swaminathan B, Doyle M, Bowen A. Efficacy of protocols for cleaning and disinfecting infant feeding bottles in less developed countries. Am J Top Med Hyg 2009; 81: 132-9.
  12. Rowan NJ, Anderson JG. Effectiveness of cleaning and disinfection procedures on the removal of enterotoxigenic Bacillus cereus from infant feeding bottles. J Food Protect 1998; 61: 196-200.
  13. D’Amico CJ, DiNardo CA, Krystofiak S. Preventing contamination of breast pump kit attachments in the NICU. J Perinat Neonat Nurs 2003; 17: 150-7.
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  15. Peters MDJ, McArthur A, Munn Z. Safe management of expressed breast milk: a systematic review. Women and birth 2016;29:473-81.