Does Reverse Osmosis Remove Fluoride, Chlorine and Lead

Does Reverse Osmosis Remove Fluoride, Chlorine and Lead?

Conspiracy theorists have long spun stories about how the government is introducing things into the water system for malicious intent. Based on their theories, it’s to ‘control the masses’ and to ‘keep us weak and dumb, so we don’t overthrow the government.’

If you’re like me… then you’d think these ideas are a bit too far fetched to be believed. However, I do believe there are chemicals in the water that do us more harm than good. They should never be in your drinking water. But does reverse osmosis actually remove fluoride, chlorine, and lead?

In a nutshell: Reverse osmosis removes all three contaminants and much more. However, chlorine is damaging the membrane, and this is why most of the RO units have the pre-filtration stage to treat the water of chlorine before it reaches the RO stage.

Now, let’s have a deeper look into this.

Reverse Osmosis Explained

To understand reverse osmosis, we must first understand the process of osmosis. Osmosis is a process that happens when a dilute solution and a concentrated solution are separated by a semipermeable membrane.

I know, I know, that doesn’t explain much, so let’s unpack that sentence.

A solution is when you mix a solute with a solvent. For example, saltwater(solution) is a mixture of salt(solute) and water(solvent). A semipermeable membrane is a layer that allows only specific molecules to pass through. It can be found within nature as well as be artificially created. In water filtration systems, a thin-film composite membrane is used.

So, if you take a U-tube with a semipermeable membrane in the middle, and add dilute saltwater in one end of the tube and concentrated salt water in the other, the water in the dilute salt water will flow into the concentrated section of the tube.

Why does this happen? That’ll take a whole lesson in thermodynamics that we won’t get into here.

But just know that water in the dilute salt water will flow into the concentrated saltwater, and will continue to flow until the concentrated saltwater reaches osmotic pressure — the minimum pressure needed to prevent the inward flow of water.

At this point, equilibrium is reached; both sides end up with the same amount of concentration.

semi-permeable membrane
By Rlawson at English Wikibooks, CC BY-SA 3.0, Link

Still with me? Good.

Osmosis is how plants absorb water from the soil. Roots have a higher solute concentration than the water in the soil, so osmosis occurs.

It’s also observed in food preservation. Fruit or vegetables are placed in a brine or syrup solution, sucking out all the water in the food. This shrinks them and preserves the food for a long time.

Now that we understand osmosis(phew!), we can understand the reverse osmosis process.

As the name implies, it’s reversing the osmosis process by applying a lot of pressure to the concentrated solution. The membrane stops all the solutes from going through – only pure water passes through.

This gives you water that is 99% free of ions, unwanted molecules, and larger particles.

Unlike standard filtration that collects the filtered material over time, reverse osmosis uses cross filtration. Cross filtration has two outlets, pure water going to your taps and the concentrated water discarded down the drain.

Now that we’re up to speed with how the system works, you’ll find out about the Big 3 contaminants.

Does Reverse Osmosis Remove Fluoride?

Fluoride is found naturally in the earth, water, and foods. However, it was introduced into tap water as a national dental health initiative in the US to curb tooth decay.

While this proved successful at improving dental health, this was back when people did not pay attention to dental hygiene, and brushing your teeth was not a natural part of daily life.

We live in a time when you can get fluoride toothpaste, so drinking this chemical is overkill.

fluorosis rates
Graph taken from

This graph shows the drastic increase in cases of children getting dental fluorosis — a disorder caused by excessive ingestion of fluoride. I’m sure you’d agree that based on the graph, what the government is doing is not working very well.

There’s a mountain of evidence that suggests fluoride’s other detrimental effects.

Many studies showed a connection between fluoride toxicity and increased autism. It also causes arthritic symptoms, and it affects thyroid function.

It. Is. Bad for you.

Which brings us to an important question…

How do I stop drinking fluoride?

Well, reverse osmosis will do just that. Because of the process’s ability to filter out ions, fluoride is effectively removed. And if you’re serious about reducing your fluoride intake, don’t use Teflon pans either as they can increase the fluoride levels in your food.

I’m sure you also know this, but since processed beverages use fluoridated water, so avoid drinking them(as much as possible.)

What about Chlorine?

You’re sure to know this chemical. You’ve been to a swimming pool and smelled its distinct odor. You’re familiar with the dry skin and hair from being submerged in it. Chlorine, while useful for keeping water uncontaminated, should not be consumed.

You don’t need me to tell you that.

Studies are showing increased rates of rectal and bladder cancer from chlorine. Food allergies have also been observed to be caused by chlorine ingestion.

The Netherlands has been leading the way with alternative methods to decontaminating water. Using a complex system that includes sedimentation and UV disinfection, the Dutch have managed to have clean water without the use of chlorine (click here to read study).

The system is effective enough to produce water that is as pure as the water from countries that use chlorine, like the US and UK. Until other states follow suit, we will just have to make do with removing it ourselves. The government has brought it to your pipes contamination-free(relatively), now it’s your job to make sure it’s chlorine-free too.

So does reverse osmosis remove chlorine?

The answer is yes, but there’s a catch. The thin-film composite membrane used in a reverse osmosis system gets damaged by free chlorine floating in the water. These filters lose their performance after about 1000 ppm.h (a measurement that factors in time exposed and the amount of chlorine in the water) of chlorine exposure.

Luckily, smarter minds working at the companies who make these filters have thought about the problem.

To solve the issue, carbon filters are installed before the reverse osmosis process. A bed of activated carbon uses chemical adsorption to remove chlorine as well as particles such as sediment, volatile organic compounds (VOCs), including taste and odor from water.

So while reverse osmosis itself cannot remove chlorine without damage, most reverse osmosis filters will filter it out using a pre-stage of carbon filters.

Does Reverse Osmosis Remove Lead Too?

This is a health crisis that rarely gets brought up even after the saddening story of the water crisis in Flint, Michigan.

It’s been shown that lead can pose a health threat even at low doses, especially for young children and pregnant women.

Like chlorine and fluoride, lead will cause brain damage in developing children while increasing the risk of cancer in adults. The Environmental Protection Agency has said that there is no safe level of lead exposure.

What that means is you should be worried.

Water leaving treatment plants are free from lead. Still, it is the delivery method that causes lead to be introduced into the water system.

The pipes carrying water into schools, offices, and your home are old — these pipes corrode, and the lead in them are then carried in the water. Even newer pipe systems are not as safe as the water they’re delivering may already be contaminated from older pipes. This is an infrastructure problem in the US that cannot be solved without significant renovations.

Waiting for the government to step in would be waiting for a miracle. If you’re using a reverse osmosis filter in your home, then you are safe.

Reverse osmosis removes lead effectively and will protect you from lead exposure.

One Important Step If You’re Using Reverse Osmosis

A reverse osmosis filter is extremely effective at giving you pure, clean water.

But the effectiveness of reverse osmosis at removing fluoride, chlorine, and lead also means it is effective at eliminating beneficial minerals like manganese, calcium, and potassium.

These minerals are needed by the body to perform at its best.

So there are a few things that can be done:

  • Take a multivitamin. Get your minerals from a supplement, and you will get much-needed minerals at optimum levels. This is the pricy solution to the problem.
  • Have a post-filter that remineralizes the water. Some water filters will come with this post-filter stage that gives you the minerals you need. Problem solved.
  • Sprinkle some Himalayan salt into the water. Himalayan sea salt or Celtic sea salt will remineralize your drinking water. These salts contain a healthy variety of minerals. Add a pinch per gallon, and you will have great tasting water. Don’t add table salt as it only contains sodium and chlorine.


So there you have it.

Reverse osmosis filters will keep you safe from fluoride, chlorine, lead, and a gang of other contaminants. You can rest easy knowing that your body is not getting poisoned. And be sure to remineralize your water to give your body hydration and nutrients it needs.

Do share your thoughts in the comments. I’d love to hear them and have a discussion with you.

  • Are you using a reverse osmosis filter? If not, what do you use to keep your water clean?
  • Do you think countries around the world need to adopt Netherland’s innovative water treatment plants?
  • What do you think it’ll cost to change the US’s piping system?
  • Have you tried the sea salt hack I shared above?

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