Reverse osmosis systems remove nearly all dissolved solids that are commonly found in drinking water.
But can a reverse osmosis water filter remove chromium-6 (hexavalent chromium)?
We’ve answered this question below.
📌 Key Takeaways:
- Reverse osmosis water filters effectively remove chromium-6 from a drinking water supply.
- These systems remove chromium-6 with two of their filter stages: the activated carbon stage and the semi-permeable membrane stage.
- There are other methods of removing hexavalent chromium that you should also consider, including ion exchange and activated carbon filters with special media blends.
Table of Contents
🤔 Does A Reverse Osmosis Filter Remove Chromium-6?
Yes, a reverse osmosis water system can remove chromium-6.
In fact, reverse osmosis is the most effective way to remove hexavalent chromium and trivalent chromium (or chromium-3) from drinking water.
So, if your water contains chromium-6, consider reverse osmosis. This system can remove the majority of total dissolved solids – and since chromium-6 is also a dissolved solid, it can be removed by the RO process.
📊 How Much Chromium-6 Can A Reverse Osmosis System Remove?
A reverse osmosis filter can remove up to 99% of hexavalent chromium in drinking water. The best RO system should be able to reduce chromium-6 levels down to below the EPA’s Maximum Contaminant Level of 0.10 PPM (parts per million).
That means your water should be free from total chromium – including chromium-6 and chromium-3 – by the time it leaves the RO faucet.
The exact amount of chromium removed depends on several factors including:
- The age of the membrane – Older, degraded membranes may be less effective at removing high concentrations of hexavalent chromium.
- The membrane quality and pore size – The higher-quality the membrane and the smaller its pore size, the more chromium-6 it should remove.
- Your water’s hexavalent chromium concentration – The higher the concentration of chromium-6, the higher the likelihood that some of the particles will slip through.
- The other contaminants in the water – Certain other impurities may interfere with the RO membrane’s ability to reduce chromium-6.
You can verify a manufacturer’s contaminant reduction claims by looking for third-party test results online. Even better if the product is officially NSF certified for its ability to remove chromium-6.
Test results will show you exactly what a system can remove, and to what percentage. If you can’t find test data for an RO water filter you’re interested in, ask the manufacturer if they can email you a copy.
🔎 How Does RO Remove Chromium-6?
There are two filter stages in an RO system that reduce chromium-6.
The first is the activated carbon filter. This filter stage uses an adsorption process that reduces chromium-6, but doesn’t remove the chemical compounds entirely.
The second stage, which is most important when it comes to removing hexavalent chromium, is the semi-permeable membrane. This membrane has tiny pores as small as 0.0001 microns. Chromium-6 particles are around 0.05 microns to 34 microns, meaning that they’re too large to pass through the membrane pores.
The result is that the chromium-6 particles – and all other dissolved solids that are larger than the membrane pores – rebound into the RO chamber, and are flushed away with wastewater.
Only the water molecules and a few particularly tiny impurities make it through the membrane and out of the RO system.
The membrane separation process continues for as long as your faucet is switched on and water is flowing through the system, so you’ll get access to purified, chromium-free water on tap whenever you need it.
🧐 Should You Use Reverse Osmosis To Remove Chromium-6?
Reverse osmosis is a highly effective chromium-6 removal method, eliminating this contaminant from your water and protecting you from its adverse health effects.
However, this water purification method might not be the best personal choice for you based on your budget and other preferences.
RO systems are expensive and require a lot of maintenance. There are numerous alternative methods that are cheaper and easier to maintain, which you might personally prefer.
When deciding whether or not an RO system is right for you, consider the following:
- Your upfront and annual budget
- Your installation and maintenance preferences
- The other contaminants you want to address in your water (if any)
- Your preferred point of filtration (countertop, under-sink, whole-home, etc.)
Once you have a list of your preferences, you’ll find it easier to choose the right type of filtration system to reduce chromium-6 in your drinking water.
🚰 Other Effective Methods Of Chromium-6 Removal
We mentioned that reverse osmosis is the best method of removing chromium-6 in your drinking water, but it’s still worth considering the other available methods, too.
Ion Exchange Water Treatment
An ion exchange water system can also be used to remove chromium-6 from drinking water.
This type of water treatment has been proven effective at removing hexavalent chromium from drinking water, but the performance of the ion exchange resin may be hindered by the presence of other contaminants, including arsenic and uranium.
Ion exchange systems are typically installed as point-of-entry filters that can remove the element chromium from your whole home’s water pipes and fixtures.
Specialized Carbon-Based Filters
There are also carbon-based filters that use a special media blend that’s capable of reducing hexavalent chromium in water.
Some countertop filters, water filter pitchers, and under-sink filters may use a special media blend for chromium-6 reduction. For instance, Berkey water filtration systems are advertised to remove chromium-6.
We recommend only buying a filter of this kind if it has third-party test results that support the manufacturer’s chromium-6 reduction claims.
📑 Final Word
If your goal is to eliminate the majority of contaminants from your tap water, including chromium-6, a reverse osmosis filtration system is ideal.
There are tens of reverse osmosis filters on the market today. We strongly recommend taking the time to do your research, compare customer reviews, and see what experts are saying about a certain product before you spend your money.