The bits and pieces that come with your breast pump need to be sterilised before you use them first, and then you need to sterilise regularly after that. How often to sterilise will depend on the age of your baby, any health issues so be guided by your healthcare professional on frequency. It can be confusing working out which breast pumps you need to sterilise / clean, so here’s our complete guide to cleaning and sterilising breast pump accessories.
Sterilise before first use
First things first, you need to sterilise your milk collection kit prior to first use, as well as any bottle accessories you plan on using for storage or feeding. Essentially, this includes anything that might come in contact with your baby’s milk:
Duck valve / valve + membrane set.
Breastshield / connector + flange set.
Backflow protector (make sure you disassemble first!).
Collection bottles.
Bottle accessories including bottle caps, necks, teats, and sealing discs.
You do not need to sterilise the following items (and in fact should not, because it will cause irreparable damage).
✘ Tubing / tubing connectors.
✘ Pump motor.
✘ Power adaptor.
✘ Milk storage bags (these come pre-sterilised).
This item cannot be sterilised in a microwave steriliser due to the metal component:
✘ Pump2bag adaptor
Sterilising in boiling water
To sterilise with boiling water, you will need a large cooking pot (such as a dutch oven) and access to a stovetop.
- Fill up a large stock pot about half way with water.
- Add your pump accessories, taking care that things are not too crowded together as that can cause warping or distortion. There must be enough room for all the items to be completely submerged and able to move freely. Make sure that items are not nested within each other (e.g. valves inside of bottles), pressed against the side of the pot, and that air has been removed bottles. Make sure that backflow protectors and valve + membrane sets have been fully disassembled, and valves have been removed from breastshields. Do not sterilise the tubing, tubing connectors, or pump motor.
- Put the pot on the stovetop over high heat, and bring to a rolling boil.
- Boil for 5 minutes.
- Remove from heat, and let cool to a manageable temperature.
- Use a clean pair of tongs to remove accessories, and lay on a clean paper towel away from a high traffic area (do not use a cloth towel as this may harbour bacteria).
- Make sure parts have been given time to completely air dry prior to assembling or storing. This is especially important for the backflow protectors. Always wash your hands before handling clean, sterile parts.
- Store parts in a clean, closed container such as a snaplock bag or food storage container.
Tip: We recommend assembling milk collection kits before storing them to reduce the risk of missing parts and make things easier when going to pump 
Sterilising in the microwave
You can sterilise your shield kit sparts in the microwave, but only if you use a sterilisation product specifically designed for pump parts. Using another container could cause serious damage to your pumping accessories, especially the fragile membranes and backflow protectors which are so important for your pump’s performance. Some brands sell disposable microwave steam bags and the same rules apply: make sure parts are fully disassembled prior to sterilising and don’t include the tubing and tubing connectors. Always follow the manufacturer’s instructions carefully.
Follow the manufacturer’s instructions when using microwave steamers to sterilise pump parts.
Do not sterilise the Pump2bag adaptor in the microwave due to the metal component
Caution: frequent sterilisation of pump parts will cause them to wear down more quickly. If you anticipate frequent sterilisation for whatever reason you should anticipate needing to replace parts, especially valves, membranes and backflow protectors, more frequently than normal. We recommend purchasing a larger quantity of spare parts, prepping them for first use via sterilisation, and having them on-hand in case you need to replace a part right away.
Sterilising with a chemical solution
We don’t normally recommend sterilising with a chemical solution (e.g. Milton’s) but if you don’t have access to potable water this is a safe way to go. Always follow the manufacturer’s instructions when using chemical solutions to sterilise.
Tip: microwave sterilisation and use of chemical solutions to sterilise parts can cause discoloration of pump parts. This is perfectly normal and does not impact the fucntionality of the parts!
Always wash your hands before handling clean, sterile breast pump accessories.
Clean pumping accessories after every use
After you use your breast pump, you’ll need to clean your milk collection kit, and if you’ve used a collection bottle and any bottle accessories, those will need to be cleaned as well.
Duck valve / valve + membrane set (make sure you remove these from the breastshield when cleaning).
Breastshield / connector + flange set.
Collection bottles.
Bottle accessories including bottle caps, necks, teats, and sealing discs.
✘ Backflow protector (you only need to clean this if you see moisture inside of the casing).
✘ Tubing (never get tubing wet. If you see moisture in the tubing, it needs to be replaced.
Clean with soap and water
To clean with soap and water, you’ll need access to a sink with warm, potable water, liquid dish soap (or soap made specifically for cleaning baby bottles), a small bottle or pipe cleaning brush (that you use only for this purpose) and a separate wash basin.
- Run the water until it gets very warm.
- Fill a clean, separate washing container with warm water and a drizzle of dish soap.
- Add your pump parts to the container and swirl around, making sure they get fully saturated.
- With clean, washed hands, thoroughly scrub every surface of each part under the water. Ensure that you get into small crevices and channels by using a the bottle brush.
- Be extra careful with the duck valves and membranes.
- Rinse each part thoroughly under warm water ensuring that no soap remains in crevices and channels. Be sure to rinse out the duck valve too.
- Set out to dry on a clean paper towel away from high traffic areas (don’t use a cloth towel is it can harbour bacteria).
- Make sure parts have been given time to completely air dry prior to assembling or storing. This is especially important for the backflow protectors. Always wash your hands before handling clean, sterile parts.
Tip: to remove extra tough fat buildup from milk, try boiling pump parts in 1 part white vinegar 3 parts water for 5 minutes, then proceed with your normal wash routine. The vinegar breaks up the grease!
Let breast pump accessories air dry on a clean paper towel away from high-traffic areas.
Caution: use a wash basin and bottle brush exclusively for your pump parts and bottle accessories. Not only does this help keep small parts like membranes and valves from going down the drain, but it’s also the CDC’s official recommendation to keep your breastmilk dishes separate from your other dishes.
Clean in the dishwasher
You may clean your breast pump accessories (except for duck valves, valve membranes, and backflow protector membranes – hand wash these fragile parts separately) in the top rack of your dishwasher on a regular dish washing cycle followed by an air dry cycle. If your pump parts are not completely dry out of the dishwasher, set them on a clean paper towel away from a high traffic area until they completely air dry. Always wash your hands prior to handling clean pump parts.
Caution: make sure you set your dishwasher to air dry, not heat dry as a heat dry cycle can cause irreparable damage to your pump parts.
Clean with wipes
Some manufacturers make disposable wipes specifically for cleaning breast pump accessories. Make sure the wipes you use are intended solely for the purpose of cleaning breast pump parts. These are great if you’re going to be out and about during the day without access to a sink. Always follow the manufacturer’s instructions. These aren’t sufficient as a long-term cleaning solution, therefore we recommend giving the parts a good thorough wash in soap and water when you get home.
Tip: if you pump multiple times a day, we recommend having two or more milk collection kits so you can always have a clean, dry one available when you need it. You can even alternate between them so one is ready to go while the other is sitting out to dry.
Remember that these instructions are generalised for use with a healthy, full-term baby and access to potable water. If your care provider has given alternative instructions for cleaning and sterilising pump parts, always adhere to those. Note that if you have a pump from another manufacturer (which may have accessories we haven’t covered here), the cleaning and sterilisation instructions may differ from ours.