What’s the difference between the filtered water that comes from the refrigerator and the filtration systems that treatment companies offer?
This is a question that we receive all the time. This entry will be a brief comparison amongst available household water filtration systems.
Most people don’t know the main differences between available household drinking water filtration systems. For example did you know that a lot of bottled water products are filtered at the same level as your refrigerator? And that refrigerator filters hold more NSF certifications than some pitcher/pour style filters that you see at the grocery store. So we will first look at who the NSF is and what their role in water filter certifications and then compare refrigerator filters to household reverse osmosis drinking water systems.
The NSF is a third party non-profit organization dedicated to public health and safety. They certify millions of products through independent testing to assure safety and compliance. NSF has three main drinking water standards whereby drinking water filters are measured 42, 53, and 58 which is reverse osmosis.
NSF 42 NSF/ANSI 42 establishes the minimum requirements for the certification of POU/POE filtration systems designed to reduce specific aesthetic or non-health-related contaminants (chlorine, taste, odor and particulates) that may be present in public or private drinking water.
The scope of NSF/ANSI 42 includes material safety, structural integrity and aesthetic, non-health-related contaminant reduction performance claims. The most common technology addressed by this standard is carbon filtration.
Basically the certification of 42 is entry level/basic water filter mainly to remove chlorine, taste, and sediment. This is a good first step to producing high quality drinking water.
NSF/ANSI 53 establishes the minimum requirements for the certification of POU/POE filtration systems designed to reduce specific health-related contaminants, such as Cryptosporidium, Giardia, lead, volatile organic chemicals (VOCs) and MTBE (methyl tertiary-butyl ether), that may be present in public or private drinking water.
The scope of NSF/ANSI 53 includes material safety, structural integrity and health-related contaminant reduction performance claims. The most common technology addressed by this standard is carbon filtration.
Although the technology looks the same as standard 42 “carbon filtration” it’s a little bit different. The filter is engineered much tighter than a regular 42 carbon filter. For example 3M has two water filters one is NSF 42 certified filtering down to 5 micron, and one that is both 42/53 certified filtering down to .2 micron. As you can see this greatly enhances the filters ability to remove a broader range of known contaminants. Now we are getting somewhere. Some select refrigerator filters have both 42 and 53 listings.
Most filters available on the market today only have a NSF 42 listing which means it only removes chlorine, taste and odor. That is a good first step but compared to the JEA contaminant list it pales in comparison when compared to higher level filters. Some select filters include the NSF 53 listing in addition to the NSF 42 listing. You will notice that the more listings a filter has the more expensive the cost. However this is a cost that I personally don’t mind paying.
What does a reverse osmosis do that NSF 42 and 53 certified filters don’t do.
A reverse osmosis goes even further than the listings of NSF 42 and 53 by de-salting the water or reducing TDS. During this process the reverse osmosis system will remove dissolved minerals, metals and salts. Here is how it is listed at the NSF.
NSF/ANSI 58 establishes the minimum requirements for the certification of point-of-use (POU) reverse osmosis systems designed to reduce contaminants that may be present in public or private drinking water.
The scope of NSF/ANSI 58 includes material safety, structural integrity, total dissolved solids (TDS) reduction and other optional contaminant reduction claims. The most common optional claims addressed by NSF/ANSI 58 include cyst reduction, hexavalent and trivalent chromium reduction, arsenic reduction, nitrate/nitrite reduction, and cadmium and lead reduction.
A reverse osmosis also removes the salt that is produced by softening water. When you install a water softener the ion-exchange process adds a trace amount of sodium to the drinking water. The reverse osmosis will remove the added sodium. My next blog is dedicated to how much salt gets added to softened water by a water softener and why does it matter. But basically, by reducing TDS (Total Dissolved Solids) the reverse osmosis will yield a product water that is considered pure. Things like salts, chromium, and other potentially harmful contaminants will not be removed by filters that are NSF 42 and 53 certified only. The 3M RO 401 holds NSF certifications 42, 53, and 58. (It’s also one of the only RO’s on the market that hold all three certifications.)
When compared to the JEA quality water report the reverse osmosis system will cover a wider range of our current contaminants making it the popular choice among homeowners. Basic carbon filters and even some more capable refrigerators cannot reduce contaminants the way a reverse osmosis can.
What Next for Drinking Water?
The next group of contaminants that are being researched currently are called “Emerging Contaminants”. These deal with prescription drugs, over the counter medications and chemical compounds. Many experts agree that the most effective method to deal with the Emerging Contaminants category is reverse osmosis. There are no MCL’s (Maximum Contaminant Levels) set for Emerging Contaminants at this time.
There are a lot of contaminants that can effect human health. Removing each contaminant is a process that can be tricky and has to be tested to certify the specific contaminant has been removed. When selecting a water filtration system select one with all three of the NSF certifications 42, 53, and 58 just to be sure.
Note: its Florida State law that all reverse osmosis systems be NSF 58 certified. Before you buy a water filter from an independent dealer clarify if it is certified then ask to see the page in the owner’s manual that lists the NSF compliance. There is a flood of cheap imported water filter systems on the market that have not been tested and listed with the NSF and therefore should not be used in Florida.