Breast Pumps & Accessories

Why This Guide Exists

A breast pump is, in many ways, the most consequential single piece of equipment a new parent who is feeding human milk will use. It is used multiple times per day, sometimes every few hours around the clock, for months. It involves direct skin contact, direct contact with breast milk, and a closed loop between a sensitive body part and a piece of medical equipment whose hygiene and fit will determine whether pumping is sustainable. And yet most new parents receive their pump through an insurance program with minimal guidance about how to choose, how to size, how to clean, or what the parts are made of.

The category has expanded significantly in the past decade. The Affordable Care Act in 2012 began requiring insurance plans to cover breast pumps without copay, which created a much larger market and a more competitive product landscape. The PUMP for Nursing Mothers Act in December 2022 expanded federal workplace protections requiring break time and a private space for pumping. The introduction of in-bra wearable pumps starting in 2017 reshaped the category, though not always in ways that pediatric authorities consider equivalent in efficacy. The result is more parents pumping more milk than at any point in U.S. history, and a more varied product market than has ever existed for the category.

The safety landscape has correspondingly become more complex. The U.S. Food and Drug Administration regulates breast pumps as Class II medical devices, which means they require 510(k) premarket clearance before sale. But FDA clearance addresses electrical safety, performance specifications, and basic biocompatibility; it does not address chemistry comprehensively, does not establish flange sizing standards, and does not regulate the proliferation of pump-adjacent accessories -- storage bags, hygiene wipes, cooling kits -- that have grown around the pumps themselves. Independent research has documented that incorrect flange sizing is widespread (most pumps ship with one default size that fits a minority of users), that some pump tubing contains PVC with phthalate plasticizers, that breast milk storage bags have tested positive for PFAS in independent investigations, and that bacterial contamination from inadequate cleaning has been associated with at least one documented infant death.

This guide covers what each pump category is and how the categories differ in performance and safety, what pump parts are actually made of, the chemicals that independent testing has documented in pump and accessory materials, the flange fit question that is the single most consequential variable in successful pumping, the hygiene practices that prevent the contamination cases that have prompted CDC guidance updates, the regulatory landscape, and the practical habits that determine whether pumping works for a family.

The Main Breast Pump Categories

Breast pumps fall into five functionally distinct categories, with significant differences in efficacy, portability, hygiene profile, and chemistry. Choosing the right category for a family's specific situation matters more than choosing the right product within a category. Many parents end up with two pumps over the course of breastfeeding -- often a primary electric double pump for home use and either a manual or wearable pump for portability.

1. Manual Pumps

Manual pumps are hand-operated devices that use a squeeze lever or piston to generate vacuum. They have no motor, no electronics, no battery, and no tubing. The entire mechanism is the flange, a one-way valve, a hand lever, and a milk collection container. Manual pumps are the simplest pumps both functionally and chemically: with no motor to off-gas, no tubing to harbor moisture, and fewer parts to clean. They are also the slowest and most labor-intensive option. They are typically used as backup pumps, travel pumps, or for parents who pump rarely. Milk output per session is lower than electric pumps for most users.

2. Electric Single Pumps

Electric single pumps express milk from one breast at a time. They consist of a motor unit, a flange and collection container, and tubing connecting the two. Electric single pumps were the most common category before the ACA expanded coverage to electric double pumps; they remain available and are less expensive than doubles. Most parents who exclusively pump or who need to pump while away from the baby for full work shifts find single pumps too slow for sustainable use. They are appropriate for occasional pumping, for users who only need to pump one side at a time, or for users supplementing nursing with limited expressed milk.

3. Electric Double Pumps

Electric double pumps express milk from both breasts simultaneously. They are now the most common category, in part because the ACA requires insurance plans to cover them. Double pumping reduces session time by approximately half compared to single pumps, and research has consistently found that double pumping results in higher milk output per session compared to single pumping the same total time. Within the double pump category there is significant variation in motor strength, suction settings (cycle speed and vacuum strength), portability, battery options, and quietness. Hospital-grade electric double pumps are a higher-tier subset addressed below.

4. Hospital-Grade (Multi-User) Pumps

Hospital-grade pumps are designed for use by multiple users in clinical settings, are typically more powerful than personal-use pumps, and are sealed against the possibility of milk or bacteria entering the motor unit. They are used in hospital NICUs and at lactation clinics, and are sometimes rented for home use in cases of preterm infants, supply issues, or specific medical needs. The FDA classifies them as multi-user devices, distinct from the single-user devices that most parents purchase. They are generally too large and too expensive for routine personal use, but their availability as rental products is a meaningful resource for parents whose situation warrants them.

5. Wearable In-Bra Pumps

Wearable in-bra pumps are a newer category, introduced around 2017, in which the entire pump (motor, milk collection cup, flange) fits inside a standard bra cup. There is no external motor unit and no tubing in most designs. Wearable pumps have transformed portability and discretion for parents who pump at work or in public; they can be worn while walking, working, or caring for the baby. The trade-offs are real and worth understanding. Most independent testing and lactation consultant consensus has found that wearable pumps produce somewhat less milk per session on average than equivalent traditional electric double pumps, with the gap depending heavily on the specific user and the specific product. The collection capacity per cup is also typically smaller (six to eight ounces per cup), which can require interruption to empty during longer sessions. Wearable pumps are typically marketed alongside traditional pumps rather than as replacements; many users own both and use them for different situations.

Categories at a Glance

Closed System vs. Open System: A Critical Distinction

Among the technical distinctions in breast pumps, none matters more for hygiene than the closed-system versus open-system architecture. The distinction is not always clearly explained in pump marketing, but understanding it changes how you should evaluate any specific pump -- particularly with regard to multi-user use, hand-me-downs, and contamination prevention.

Closed-System Pumps

A closed-system pump includes a physical barrier -- typically a backflow protector or membrane -- between the milk collection container and the tubing that runs to the motor. Milk cannot enter the tubing during normal operation; any condensation that forms in the tubing cannot reach the milk; and bacteria, mold, or other contaminants that might accumulate in the motor or tubing cannot reach the milk. Closed-system pumps are inherently safer for shared or multi-user contexts, easier to clean, and less prone to contamination problems over time. The CDC and most lactation organizations recommend closed-system pumps as the cleaner choice.

Open-System Pumps

An open-system pump does not include a backflow barrier. Milk can flow into the tubing during operation, and the tubing connects directly to the motor without a sealed interface. Some major personal-use electric pumps are still designed as open systems. Open-system pump tubing can become soiled with milk over time, can develop bacterial or mold contamination in the tubing itself, and cannot be safely shared between users because contamination can pass from the tubing to the next user. Open-system pumps are not unsafe for single-user home use if the tubing is replaced when soiled and the cleaning protocols are followed, but they require more vigilance than closed-system pumps.

Why It Matters for Hand-Me-Downs

An open-system pump that has been used by a previous user cannot be safely reused by a new user simply by replacing the tubing. The motor itself may contain bacteria, mold, or other contaminants that have migrated through the open tubing during the previous user's pumping sessions. The FDA explicitly classifies most personal-use breast pumps as single-user devices, which means they are not intended for use by multiple individuals. A closed-system pump can in some cases be safely passed to a new user with replacement of all milk-contact parts and tubing, but only if the closed-system barrier has remained intact and the pump has not been damaged. The conservative answer is that pumps are single-user products. If a previous pump is being considered for a new user, a closed-system pump with a verified intact barrier is the only configuration in which this should be contemplated -- and a new pump is meaningfully safer.

What Breast Pump Parts Are Actually Made Of

A typical breast pump kit consists of six to ten components, each with its own material composition. The components that come into contact with milk are the most consequential from a chemistry standpoint, because anything that migrates from those materials can be ingested by the baby through the milk. The components that contact the breast but not the milk are the next most consequential, since prolonged skin contact is its own exposure route.

The Flange (Breast Shield)

The flange is the funnel-shaped piece that fits over the nipple and creates the seal through which the pump generates vacuum. Flanges are typically made of polypropylene (a clean, bisphenol-free plastic), silicone, or a polypropylene flange with a silicone insert. Silicone flanges and silicone inserts have become more common because they are softer against the breast and conform to varied anatomies. Quality silicone (medical-grade, platinum-cured) is generally inert and safe; lower-grade silicone may release residues during heat sterilization. Polypropylene is also generally clean. Avoid flanges with vinyl, PVC, or unidentified soft plastic components, which can contain phthalate plasticizers.

The Tubing

Tubing connects the milk collection cups to the motor unit on traditional pumps (both closed and open system, though wearable pumps generally have no external tubing). Tubing material is one of the most variable chemistry components in the pump system. Higher-end pumps use silicone or polyurethane tubing, both of which are relatively clean. Some pumps, including some major-brand products, use PVC tubing, which requires phthalate plasticizers to be flexible. Phthalate exposure through tubing is a documented concern, particularly because the tubing is in close proximity to -- and in open-system pumps, in contact with -- breast milk. The leaching rate for phthalates is higher for fatty substances like breast milk than for non-fatty substances. The chemistry of any specific pump's tubing should be verifiable from the manufacturer; if not disclosed, treat as PVC by default.

The Bottles and Collection Containers

Milk collection bottles attached to the pump and standalone storage bottles are typically polypropylene (PP, recycling code #5), glass, or in some cases polyethylene. Polypropylene is inherently bisphenol-free by polymer chemistry -- not by reformulation -- and is generally the safest plastic option for milk contact. Glass is the cleanest material categorically: no leaching, fully recyclable, easy to sterilize, though heavier and more fragile. Polycarbonate (recycling code #7), which was the original common material before the BPA controversy, has been largely phased out from pump bottles but may still appear in older and legacy products. Avoid any pump bottle of unspecified plastic type.

The Valves and Membranes

Valves and membranes are typically silicone, with quality varying widely. These are the parts that experience the most mechanical wear during use and are the parts that most commonly need replacement -- every two to three months for daily use according to most manufacturers. A worn valve creates inefficient suction and reduces milk output; it can also be a site of bacterial accumulation. Replacement valves and membranes are inexpensive but require regular attention that pump manufacturers do not always emphasize prominently.

Storage Bags

Single-use breast milk storage bags are typically polyethylene (PE) or a multi-layer plastic film with PE inner surfaces. The interior surface is the only material in direct milk contact for most designs. Some storage bags have been independently tested and found to contain PFAS, particularly in the heat-seal seam or in coatings used to make the bags freezer-safe and microwave-safe. Reusable silicone or glass storage containers are an alternative that avoids the single-use plastic and the seam chemistry concerns, with the trade-off of more cleaning.

The Motor and Housing

The motor unit (the piece that does not contact milk or skin) is typically ABS plastic, polycarbonate, or polypropylene housing around the motor itself. The motor housing is generally not a chemistry concern since it does not contact milk or skin. Wearable in-bra pumps locate the motor inside the bra cup, which means the motor is now adjacent to the breast and in some cases near the skin. The electromagnetic exposure from a small DC motor at this proximity is generally considered low, but it is one of the considerations that distinguishes wearable pumps from external-motor designs.

Chemicals Found in Pumps and Accessories

The following chemicals have been documented in commercially available breast pump components and accessories through independent testing, peer-reviewed research, or regulatory enforcement. The breast pump is unusual in the baby product chemistry context because it is a food-contact device for a substance that is directly ingested by the baby -- which makes the migration of any chemical from pump materials directly into the milk a meaningful exposure route.

Chemicals at a Glance

Flange Fit: The Single Biggest Variable in Pump Success

Of all the variables in breast pumping success, flange size is probably the most consequential and the most under-discussed in standard pump marketing. The vast majority of breast pumps ship with a default flange size of 24mm. The vast majority of breastfeeding parents have nipple diameters that do not match the 24mm flange. The result is widespread experience of pain, low milk output, clogged ducts, and premature weaning that is often attributed to other causes when the underlying issue is a mechanical mismatch between the flange and the user's anatomy.

What a Flange Actually Does

The flange is the funnel-shaped piece that fits over the nipple and creates the vacuum seal through which the pump operates. The tunnel of the flange is the cylindrical section that the nipple passes into during pumping. The diameter of the tunnel must match the diameter of the nipple closely enough that the nipple moves freely without rubbing the tunnel walls (which causes pain and damage), but tightly enough that the seal directs vacuum to the nipple rather than to surrounding areola tissue (which reduces milk extraction). Both under-sizing and over-sizing produce different failure modes that are identifiable with the COMFY test described below.

How to Measure

Measurement is straightforward but requires precision. Using a ruler or measuring tape calibrated in millimeters, measure the diameter of the nipple at the base where it meets the areola. Do not include the areola in the measurement; the flange tunnel is sized to the nipple shaft, not to the breast tissue around it. Stimulate the nipple briefly before measuring to assess size at typical pumping conditions, but do not pump or nurse immediately before measuring as the nipple will be temporarily enlarged. Measure both sides; many parents have slightly different sizes between left and right and benefit from different flange sizes per side. Nipple sizes can also change during the breastfeeding journey, particularly in the first weeks postpartum, so measurements should be repeated periodically.

How to Size

The traditional guidance has been to choose a flange that is approximately three to six millimeters larger than the nipple diameter -- so a 19mm nipple would suggest a 21mm or 24mm flange. This guidance has been the lactation consultant standard for decades. A 2024 pilot study published in the Journal of Human Lactation (Anders et al.) examined this assumption and found that for some parents, a flange size closer to the actual nipple diameter (with little or no added margin) produced better comfort and milk output. The standard of care is in active reassessment. Lactation consultants increasingly recommend trying multiple flange sizes to find the one that works best for the individual rather than assuming a single formula applies. The simplest rule: pumping should not hurt. If pumping hurts at the manufacturer-supplied default size, the flange is very likely the wrong size.

The COMFY Test

Lactation consultants use the COMFY test to assess flange fit during a pumping session. Each letter maps to a specific observable criterion:

• C -- Centered nipple in the tunnel, not rubbing the sides or pulling to one side.
• O -- Only a little areola pulled into the tunnel. Too much areola means the flange is too large.
• M -- Motion of breast gentle and rhythmic during pumping cycles, not pulling or distorting painfully.
• F -- Feels good (no pain, burning, or discomfort during the session).
• Y -- Your breast feels softer after pumping, indicating effective milk removal.

A correctly fitted flange satisfies all five criteria. Specific failure modes point at specific adjustments: too much areola pulled in suggests the flange is too large; nipple rubbing the tunnel walls suggests the flange is too small; uneven breast emptying after pumping suggests poor fit overall.

Flange Sizes and Inserts

Flanges are available in sizes ranging from approximately 10mm to 40mm, in increments of about three millimeters. Major brand pumps typically ship with a 24mm flange and sometimes a 27mm or 28mm as a second option. Most users do not actually need 24mm, but the default exists because it accommodates the broadest single-size market. Silicone flange inserts, which fit inside a 24mm flange and reduce the effective tunnel diameter to a smaller size, have become widely available and are often a more accessible and less expensive solution than purchasing entirely new flanges. Inserts are available in sizes from 13mm to 21mm, allowing extensive downsizing from the default.

Hygiene: CDC Guidelines and the Cronobacter Case

Breast pump hygiene is treated by the CDC, lactation organizations, and pediatric medicine as a medical hygiene issue, not a routine dish-cleaning task. The reason is documented: bacterial contamination from inadequate cleaning has been associated with at least one infant death, and the bacterial species involved (cronobacter sakazakii) is rare but disproportionately lethal in premature infants and immunocompromised newborns. The CDC updated its breast pump hygiene guidelines in 2017 following the documented 2016 case, and those guidelines represent the current consensus standard of care.

The 2016 Cronobacter Case

In April 2016, a Pennsylvania premature infant born at 29 weeks gestation died from cronobacter sakazakii bacterial infection. Public health investigators traced the source to contaminated breast pump parts used by the mother. The mother had washed the parts in soapy water but had not scrubbed or sanitized them, and had air-dried them on a non-sterile surface. Cronobacter thrives in dry conditions and can colonize surfaces that appear visually clean. The case prompted the CDC to issue updated guidelines that specifically address the gaps the case revealed: cleaning is not the same as sanitizing, air drying must be on a dedicated clean surface, the protocol should include daily sanitization in addition to per-use cleaning, and for premature or immunocompromised infants, sanitization is required after every use.

Before Every Pump Session

• Wash hands thoroughly with soap and water for at least 20 seconds.
• Inspect the pump kit and tubing for visible mold or soiling. If mold is present, discard and replace immediately -- do not attempt to clean moldy tubing.
• Clean pump dials, power switch, and the pumping surface with a disinfectant wipe, especially if the pump is in a shared or clinical setting.

After Every Pump Session

• Disassemble all parts that come into contact with milk: flanges, valves, membranes, connectors, and milk collection bottles.
• Rinse parts under running water to remove milk residue before washing.
• Place parts in a wash basin used only for infant feeding items -- not the regular kitchen sink, which can harbor bacteria from food handling.
• Wash with hot soapy water and a brush dedicated to infant feeding items. Some parts can be washed in the dishwasher (top rack, away from the heating element) if the manufacturer's instructions permit.
• Rinse with fresh water.
• Air dry on a clean paper towel or clean dedicated dish towel, never on a regular towel that may harbor bacteria.
• Once completely dry, store the reassembled pump kit in a sealed protected area such as a sealed food storage bag.

Daily Sanitization

• In addition to washing, sanitize pump parts at least once per day. Sanitizing methods include steam sterilization, placing parts in boiling water for five minutes, or running through a dishwasher cycle with a sanitize setting.
• For premature infants, immunocompromised infants, or infants under two months of age, sanitization should be performed after every use, not just daily.

Tubing-Specific Care

• In closed-system pumps, tubing does not contact milk and does not need routine internal cleaning. Wipe the exterior with a damp cloth if soiled.
• In open-system pumps, or if milk has entered the tubing for any reason, the tubing must be discarded and replaced. Tubing that has accumulated milk inside is essentially impossible to fully clean and is a documented site of mold and bacterial growth.
• If condensation forms in the tubing at the end of a pumping session, disconnect the tubing from the flange but leave it attached to the pump, and run the pump for a few minutes to dry the condensation through airflow.
• Keep a spare set of tubing on hand at all times for prompt replacement.

Replacement Schedule

• Valves and membranes: every two to three months for daily use, sooner if signs of wear appear. A gradual decline in milk output is often the first sign that valves need replacement.
• Flanges and breast shields: every six months, or sooner if discolored or cracked.
• Tubing: replace immediately if any milk enters or if condensation persists despite drying; otherwise every six months for regular use.
• Bottles and collection containers: replace if cracked or cloudy; otherwise can be used as long as they remain washable and undamaged.

Regulations and Certifications: What They Actually Mean

The breast pump regulatory landscape is materially different from other baby product categories because breast pumps are medical devices, not consumer products, under U.S. law. This distinction has consequences for which standards apply, which do not, and where the chemistry gaps are.

Certifications at a Glance

How You Use the Pump Matters

Beyond product choice, several practical habits substantially affect both safety and the success of pumping. These are drawn from CDC, lactation consultant, and pediatric guidance and address the most common points of failure.

How to Shop Smart: A Decision Framework

Breast pumps sit at an unusual intersection of medical device regulation, consumer product marketing, insurance procurement, and personal anatomical fit. The decisions that matter most are largely invisible at purchase time. The framework below organizes them from absolute non-negotiables through the chemistry and feature gradients within a safe baseline.

A Word on Wearables vs. Traditional Pumps

Wearable in-bra pumps and traditional external-motor electric double pumps are not directly substitutable for most users. Wearables offer portability and discretion that traditional pumps cannot match; traditional pumps offer typically stronger suction, larger collection capacity per session, and -- depending on the specific products compared -- higher average milk output. The honest answer for most exclusively pumping or working parents is that some combination of both is the optimal solution: the traditional pump for home sessions when output and efficiency matter most, the wearable for situations where mobility or hands-free operation matter more. Both are FDA-cleared, both have material and chemistry considerations to verify, and the decision framework applies to both equally.

A Word on Pump Costs and Insurance

Most U.S. parents are eligible for an insurance-covered breast pump through ACA provisions. The specific pumps covered vary by insurer, and the available options through the DME supplier may not include all market models. Many insurers cover only one pump per pregnancy. Out-of-pocket upgrades or secondary pumps (a wearable in addition to a traditional pump, for example) are typically not covered. Health Savings Accounts and Flexible Spending Accounts can typically be used for out-of-pocket pump purchases. If a wearable is part of the plan but not insurance-covered, that purchase typically falls between $200 and $500.

The Bottom Line

Breast pumps sit at an unusual intersection of medical device, consumer product, baby gear, and personal anatomical fit. They are regulated by the FDA as Class II medical devices but are purchased like consumer products, often through insurance suppliers with limited model selection. The performance of any specific pump depends heavily on factors that are largely invisible at purchase time: the flange fit relative to the user's anatomy, the specific tubing material the manufacturer chose, whether the pump architecture is closed-system or open-system, and the cleaning and replacement habits the user adopts.

Sources & Further Reading

1. Centers for Disease Control and Prevention. How to Keep Your Breast Pump Kit Clean. Updated guidelines following 2016 cronobacter sakazakii case. cdc.gov/hygiene/about/about-breast-pump-hygiene.html
2. Centers for Disease Control and Prevention (2016-2017). Updated breast pump hygiene guidelines following documented cronobacter sakazakii infant death case in Pennsylvania, April 2016. cdc.gov
3. U.S. Food and Drug Administration. Breast Pumps: regulation as Class II medical devices and 510(k) requirements. fda.gov
4. Affordable Care Act (2012). Insurance coverage requirements for breast pumps and lactation counseling without copay. hhs.gov
5. Providing Urgent Maternal Protections (PUMP) for Nursing Mothers Act of 2022. Federal workplace pumping protections. dol.gov
6. Anders LA, Mesite Frem J, McCoy TP (2024). Flange Size Matters: A Comparative Pilot Study of the Flange FITS Guide Versus Traditional Sizing Methods. Journal of Human Lactation, 41(1):54-64. doi:10.1177/08903344241296036
7. Trasande L (2024). Making invisible chemicals used in plastic materials visible. EBioMedicine. doi:10.1016/j.ebiom.2024.105422
8. Environmental Health Perspectives. Research on bisphenol A replacement compounds (BPS, BPF) and endocrine activity. ehp.niehs.nih.gov
9. Environmental Science and Technology Letters (2023). Microplastic and nanoplastic release from microwave-heated plastic food containers.
10. U.S. Environmental Protection Agency. PFAS Strategic Roadmap and health advisory levels for PFOA and PFOS. epa.gov
11. U.S. Consumer Product Safety Commission. CPSIA requirements for children's products including pump accessories. cpsc.gov
12. U.S. Food and Drug Administration. 21 CFR Part 177 food contact material regulations. fda.gov
13. LFGB Standard. German Food and Consumer Goods Act food contact testing requirements. bfr.bund.de
14. OEKO-TEX. STANDARD 100 testing criteria and certified product directory. oeko-tex.com
15. Cleveland Clinic. Breast Pump Flange Sizing Guide. health.clevelandclinic.org
16. International Lactation Consultant Association. IBCLC resources and consultant directory. ilca.org
17. United States Lactation Consultant Association. IBCLC information and education resources. uslca.org
18. Endocrine Disruption Exchange. Research on bisphenols and reproductive health. endocrinedisruption.org