Cleaning a Momcozy breast pump involves disassembling the milk-contact parts after every use, washing them with warm soapy water, and letting them air dry completely before reassembling. The motor unit never goes in water. Getting this right matters more than you might think: the CDC has linked contaminated breast pump equipment to serious infant infections, including a case where bacteria on a home breast pump genetically matched the infection in the baby’s bloodstream.
Which Parts Get Washed (and Which Don’t)
Every Momcozy wearable pump, whether it’s the S9, S12, or a newer model, breaks down into two categories: parts that touch breast milk and the electrical motor unit that powers everything. Only the milk-contact parts get washed. These include the flange (the piece that sits against your breast), the collection cup, the duckbill valve, and the silicone diaphragm.
The motor unit should never be submerged, rinsed under a faucet, or run through a dishwasher. To clean it, wipe the exterior with a disinfectant wipe, paying attention to the buttons and any surface that your hands touch regularly. If milk has splashed onto the motor housing, a damp cloth will do. Just make sure no liquid enters the charging port or any openings.
How to Wash After Every Use
Take the pump apart as soon as you finish a session. Breast milk residue dries quickly and forms a film that gets harder to remove the longer it sits. Rinse all milk-contact parts under running water first to clear out visible milk, then wash each piece with warm water and regular dish soap. The CDC specifically recommends against antibacterial soap for breast pump parts, since it can contain additives that aren’t proven safe for daily use on equipment that contacts breast milk.
If your model came with a small cleaning brush, use it to get inside narrow openings like the flange neck and the duckbill valve. These tight spots trap milk fat and can develop buildup that’s invisible but provides a surface for bacteria to grow. Work the brush through each part with soapy water, then rinse thoroughly until no soap residue remains.
A note on wipes: quick-clean wipes designed for breast pump parts are convenient when you’re at work or traveling, but the FDA considers them a temporary measure. Parts that contact breast milk still need a full wash with soap and warm water before you use them again.
Drying the Right Way
How you dry your pump parts is just as important as how you wash them. Place all washed components on a clean, dedicated drying rack or a fresh paper towel and let them air dry completely. Do not towel-dry them, wave them around to speed things up, or blow on them. Each of those methods introduces bacteria from the towel, your hands, or your mouth directly onto a surface that will contact your baby’s food.
Assembling the pump while parts are still damp is a real risk. In a CDC-investigated case, an infant developed a severe Cronobacter sakazakii infection, a type of bacteria that causes meningitis and sepsis in young babies. The investigation found that the family’s breast pump parts were sometimes put back together while still moist. The bacteria recovered from the home breast pump was a near-perfect genetic match to the bacteria in the baby’s bloodstream. Complete drying before reassembly eliminates the warm, moist environment these organisms need to multiply.
Sterilizing for Extra Protection
Daily washing with soap and water handles routine cleaning. Sterilizing goes a step further by killing microorganisms that soap alone may not eliminate. You don’t necessarily need to sterilize after every single session, but doing so at least once a day is a solid practice, especially for younger or premature infants whose immune systems are still developing.
Momcozy’s silicone and plastic parts can tolerate temperatures up to 100°C (212°F), which means both boiling and steam sterilization are safe options. To boil, place the disassembled parts in a pot of water, bring it to a rolling boil, and keep them submerged for five minutes. Use tongs to remove them and place them on a clean drying surface. Electric steam sterilizers work the same way, just follow the sterilizer’s cycle instructions. Many Momcozy users run their parts through a steam sterilizer after nearly every use without damage to the components.
If your dishwasher has a sanitize cycle, the milk-contact parts can go on the top rack. Avoid the heated dry cycle if possible, as prolonged high heat beyond what’s needed for sanitizing can warp thinner plastic components over time. Always confirm with your specific model’s manual, since part materials can vary slightly between Momcozy versions.
Replacing Valves and Diaphragms
Even with perfect cleaning, the small silicone parts that create suction wear out. The duckbill valve and the diaphragm are the two components that degrade fastest. When a duckbill valve loses its shape or develops small tears, suction drops and your pump becomes less effective. You may notice longer pumping sessions or lower output before you can see any visible damage.
Replace duckbill valves and diaphragms every two to three months. If you’re pumping frequently, closer to every two months is better. These parts are inexpensive and sold in multi-packs. Keeping a spare set on hand means you won’t be caught with a pump that suddenly feels weak during a workday or overnight session.
Keeping Things Clean Between Washes
Where you pump and where you set your parts down matters. Before each session, wipe down the surface where you’ll place the pump and its components, especially in shared spaces like a workplace lactation room. A quick pass with a disinfectant wipe over the countertop, any nearby switches, and the pump’s exterior buttons reduces the chance of picking up environmental bacteria.
Store clean, fully dry parts in a sealed container or a clean zip-top bag rather than leaving them out on a counter between uses. Dust, pet dander, and kitchen aerosols can all settle on exposed parts. A dedicated microwave steam bag or a small lidded container works well and keeps everything together so you’re not hunting for a duckbill valve at 2 a.m.