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What Do Refrigerator Water Filters Filter Out? Find Out the Answer

Fact checked by Stephen Conklin

What Do Refrigerator Water Filters Filter Out

Have you ever asked yourself “what do refrigerator water filters filter out?” You are not alone. I asked the same question myself. For many years, I pondered if the water filter in my fridge removes the substances it claims it eliminates. After all, we do not want these impurities entering our bodies.

Unfortunately, not all refrigerator water filters remove all impurities and contaminants. Some are more successful at reducing the levels of some pollutants, while others excel at other substances. The point is that you must learn the type of filter(s) present in your fridge to know what compounds it filters out.

Table of Contents

Why Do I Need a Water Filter for My Refrigerator?

Let us first understand why we need to filter our water before looking at the different substances your refrigerator water filter removes.

Your refrigerator connects to a water supply run coming from the municipal or city water utility or the backyard well. Unfortunately, there is no telling what substances might be present in the water that reaches your refrigerator.

The Centers for Disease Control and Prevention says that US families are luckier than households in other countries because they have one of the safest water systems on the planet.

Unfortunately, the Environmental Protection Agency and the CDC also report an emerging public health concern – the levels of lead, other heavy metals, agro-industrial chemicals, pharmaceutical agents, and other contaminants in our water.

Would you risk your health and safety and that of your family by drinking unfiltered water from your refrigerator? Would you use ice from your refrigerator icemaker for your drinks?

Water filters are as important as air filters, reducing potential contaminants in your drinking water and contributing to better health.

What Do Sediment Refrigerator Water Filters Remove?


Refrigerators with sediment filters can remove large particles from your water. The impurities can include sand, dirt, silt, rust, scale, and other substances with a diameter of at least 5 microns.

You must know that different filter manufacturers rate their products according to the smallest particle size they can filter out. For example, a 10-micron sediment filter can remove more water impurities than a 20-micron filtration device.

Any particle smaller than the filter’s minimum micron size will pass through the pores. Hence, you cannot expect a sediment filter to remove heavy metals, VOCs, germs, and other microscopic compounds.

The good news is that it is rare to find a sediment-only water filter for refrigerators. It is almost always in combination with another filtration technology. An excellent example of such a product is the EcoPure EPINL30, which incorporates a sediment filter and a CTO filter in its design.

What Do Carbon Refrigerator Water Filters Filter Out?

If your refrigerator features an activated carbon water filter, you are in luck because it removes more contaminants than any sediment-only filter can.

Carbon filters work in two ways. First, it attracts water impurities like magnets pulling on metallic ions. This action makes it effective in removing more microscopic particles. It is mind-blowing to learn that a pound of carbon material has a surface area of up to 150 acres.

Second, it traps large organic molecules and particles inside microscopic crevices or pores.

The secret is in the carbon filter’s unique construction. Manufacturers mix various carbon-based materials, such as coconut shells, to form a block. The flat surfaces serve as magnets, while the pores act like traps.

Like sediment filters, carbon filtration devices have varying pore sizes. High-end carbon filters can trap microscopic particles as tiny as 0.1 microns in diameter.

So, what can a carbon water filter remove? Depending on the pore size, it can remove chlorine and its unfavorable odors and tastes. It can also remove dissolved gases and organic chemicals, including pesticides, trichloroethylene, PCBs, and THMs.

A few water filters can remove lead, coliform, bacterial cysts, fungi, waterborne parasites, pharmaceuticals, bacteria, asbestos, and other harmful compounds.

An excellent example of such a refrigerator water filter is the EveryDrop EDR1RXD1, capable of eliminating up to 99% of lead and 27 other contaminants. This water filter also has NSF certification to support its claims.

What Do Ultra-filtration Refrigerator Water Filters Reduce?


If carbon filters can remove particles as tiny as 0.1 microns in diameter, ultrafiltration membranes can trap microscopic compounds as small as 0.01 microns in diameter.

The ultrafilter’s pore size is so small it can remove some viruses. Of course, you cannot expect the filter to kill the virus. At least, it can prevent these microorganisms from getting into your drinking water.

Unfortunately, the downside of an ultrafiltration membrane is that it clogs easily. That is why many manufacturers combine it with either a sediment filter or an activated carbon filter, or both. The first two filtration membranes trap larger molecules before passing them to the ultrafilter.

What Do Kinetic Degradation Fluxion Refrigerator Water Filters Filter Out?

Some refrigerators feature a unique water filter known as Kinetic Degradation Fluxion (KDF) filtration technology. This filter mechanism works by donating two electrons to every molecule in the water, following the principles of an oxidation-reduction chemical reaction.

This type of filter is perfect for removing up to 99% of chlorine and up to 95% of hydrogen sulfide, iron, mercury, lead, copper, other heavy metals, and other substances.

The redox reaction also makes the water inhospitable to some microorganisms, such as bacteria.

The filter can also increase the longevity of activated carbon filters. That is why many manufacturers add a KDF component to their carbon filtration system.

A good refrigerator filter with a KDF technology is the Watts 43000140 Inline Water Filter, complete with WQA certification.

What Should I Look for in a Refrigerator Water Filter to Remove All Contaminants?

I understand your eagerness to remove as many contaminants as possible from your water. Unfortunately, there is no single product that can remove ALL known water impurities.

According to the CDC, households can use a combination of water treatment systems to get the purest water for their families. The treatment options include water filtration systems, water softeners, reverse osmosis technologies, and UV treatment systems.

It would be impossible to pack these technologies into a compact canister that fits into the refrigerator water filter compartment.

Nevertheless, you can always look at the list of contaminants a water filter can remove. Note the level of reduction the product offers and whether it has the appropriate third-party quality certifications to support its claims or not.


Knowing what do refrigerator water filters filter out can help you choose the right type of water filtration system to put in your fridge. It ensures clean, odor-free, safe, and great-tasting drinking water straight from the refrigerator. You can also create more fascinating drinks with crystal clear ice.

What is essential is to look at the contaminants manufacturers list in their refrigerator water filters. More importantly, you must check if it has the correct certification as evidence of its filtration performance.

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