Closed System vs Open System Breast Pumps Explained

You'll see 'closed system' mentioned constantly in pump reviews — but what does it actually mean, and why does it matter? Here's a plain-language explanation.

Spectra Baby Canada · 5 min read

When you start researching breast pumps, you'll quickly run into the terms "closed system" and "open system." It sounds technical, but the concept is simple — and it has real implications for hygiene and maintenance. Here's what you need to know.

What is a closed system?

A closed system pump has a barrier — called a backflow protector — between the milk collection area and the tubing/motor. This barrier prevents milk, moisture, and air particles from ever traveling up into the tubing or the pump mechanism. The milk stays completely contained in the parts you can see and wash.

What is an open system?

An open system pump has no such barrier. There's a direct air pathway between the milk and the tubing/motor, which means milk particles and moisture can potentially make their way into the tubing — and, in some cases, the motor itself.

Why the difference matters

Hygiene

In a closed system, because milk can't enter the tubing or motor, there's far less risk of mold, mildew, or bacteria building up in places you can't easily clean. This is the single biggest reason closed systems are preferred.

Easier maintenance

With a closed system, you don't need to routinely wash the tubing, because milk never touches it. That's a real time-saver. With an open system, moisture in the tubing needs to be managed and the tubing cleaned more carefully.

Longevity and resale

Because nothing contaminates the motor, closed-system pumps maintain hygienic performance over time.

The bottom line

For most parents, a closed system is the clear choice: better hygiene, less cleaning, and peace of mind that the milk path stays sealed. When comparing pumps, checking whether a model is closed-system is one of the most useful filters you can apply. Learn more in our Spectra vs Medela comparison.

This article is for general educational purposes only and is not medical advice. Every breastfeeding journey is different. Please consult your doctor, midwife, or a licensed lactation consultant for guidance specific to you and your baby.