Refrigerator filters are an increasingly common addition to modern households as people look to improve the quality of the water they drink every day. The idea of filtering water sounds great, but an important consideration is what the filtering actually does — and do refrigerator filters remove E. coli?
Most refrigerator filters do not remove E. coli. A typical refrigerator filter is comprised of a particle filter to remove suspended particles and a carbon filter that removes chlorine and improves taste. The treatment technologies included in a refrigerator filter do not remove bacteria such as E. coli.
Knowing what your refrigerator filter removes isn’t as obvious as you might expect. Keep reading to learn more about what refrigerator filters do and how to reduce your risks from E. coli and other bacterial infections associated with your drinking water.
Read my ultimate guide on refrigerator filters.
Table of Contents
What Does a Refrigerator Filter Do?
Most refrigerator filters contain a particle filter and a simple carbon filter. This combination works to treat the water with three different focus areas:
- Sediment and contaminants
- Volatile organic compounds
- Chemicals
The filters usually include a mechanical filter, where the water flows through a porous media that has a large surface area. This is effective at trapping suspended particles, such as sediment and rust, that can foul and plug up the water dispenser and ice maker. Most people would be surprised at the amount of dirt and debris that is in their water supply!
The activated carbon in these filters removes volatile organic compounds (VOCs) which are usually man-made compounds that have made their way into the water supply. These contaminants are generally in very low volumes but are not good for health. They include additions like:
- Gasoline
- Cleaners
- Degreasers
- Solvents
- Dyes
- Paints
- Inks
Finally, activated carbon is also very effective at reacting with certain chemicals, which can remove them from filtered water. Carbon works through a process known as adsorption and is very effective at removing many contaminants from water. The most prominent example of that is chlorine, which is commonly found in most treated drinking water and is responsible for an unpleasant taste.
Read my article about how well refrigerator filters remove chlorine.
Which Types of Refrigerator Filters Remove E. coli?
In order to understand what special types of filters can be used to remove E. coli from the water being filtered, we should first look at exactly what E. coli is.
What is E. coli?
E. coli is short for Escherichia coli, the name of a bacteria. This bacteria is often found in animal intestines and can benefit the host by producing vitamin K — as well as providing pathogen resistance through reducing the amount of attack surface of the intestines.
Most strains of E. coli are harmless; however, a small number are responsible for an aggressive immune response, with symptoms including:
- Vomiting
- Headache
- Stomach cramps
- Dehydration
- Diarrhea
E. coli in drinking water is rare, but it can happen and it is usually a sign of sewage managing to make its way into the water supply.
Which Filters Can Remove Bacteria?
There are a number of specialized filters which are effective at removing E. coli. They take different approaches, but all address the issue by killing the bacteria in different ways. The types of filters are:
- UV light
- Chemical disinfectant
- Reverse osmosis
Read my article on how to remove bacteria from drinking water for a detailed discussion.
1. UV light
UV light filters use ultraviolet light to break down the DNA in the bacteria cells, ensuring that they are unable to reproduce. These filters are usually applied at the water entry point to the property in order to make use of the filter across the whole supply.
2. Chemical disinfectant
These filters can also remove E. coli and rely on a chemical disinfectant matrix in order to disinfect the water. This requires that the filter be porous to a specific size of the particle to increase the ability of the filter to react chemically with the contaminant. As E. coli is a frequent concern when filtering the water, it should be well-documented whether a specific filter is adequate to catch E. coli.
3. Reverse osmosis
Reverse osmosis uses a semi-permeable membrane in order use the process of osmosis to purify the water. The water will, over time, diffuse through the semi-permeable membrane in order to balance its distribution.
Depending on the implementation, it’s difficult for reverse osmosis to guarantee the capture of E. coli, so care should be taken.
How Can I Sanitize a Refrigerator Filter?
The right way to sanitize your refrigerator filter will depend mostly upon the type that you have. It’s also worth bearing in mind that also all refrigerator filters will come with guidance as to their expected lifespan — often around six months. After this point, the filter should be replaced in order to ensure that the activated carbon surface is still readily available for purification.
If your filter is still within its lifespan, check the instructions to ensure there is no risk of damage. Provided cleaning is allowed, the following steps should be followed:
- Remove large particles
- Wipe down using a cleaning solution
- Air dry
1. Remove large particles
In the process of filtering water, the filter can be vulnerable to a process called calcification, where a hard residue can build up, usually of calcium carbonate or other insoluble calcium compounds. Where this is the case, review the filter and manually remove any obvious residue.
2. Wipe down using a cleaning solution
Using a gentle cleaning solution will ensure that the filter is not damaged by the use of stronger chemicals. A small amount of dish soap or vinegar mixed with water will be adequate. With this prepared, take a cloth and use it to wipe over the filter, visually inspecting it for signs of residue.
3. Air dry
As the cleaning process will add moisture to the filter, it’s important to allow it to thoroughly air dry once clean. This is because a moist environment is more likely to result in bacterial buildup due to it providing a more desirable place for them to hide.
Once completely dry, the filter can be reinserted back into the refrigerator. You may wish to allow several glasses of water to be filled and disposed of to ensure that no cleaning solution remains within the water.
Conclusion
It’s clear that being aware of what your refrigerator filter does and doesn’t remove is important. By understanding the risks that E. coli poses as well as the type of refrigerator filter you have, you’ll be in a better position to assess how to reduce the risks of E. coli in your drinking water.