What is the activated carbon filter? Pros and cons? How long can you use an activated carbon filter?

A closeup shot of natural stones

Since as far back as 3,750 BC, people have been using carbon or charcoal to filter things. Back then, the ancient Egyptians used it to get rid of bad smells. Over the next five and a half thousand years, sailors used it to keep their water clean during long journeys. Nowadays, most air filters contain something called activated carbon. This is just carbon or charcoal that’s been treated in a special way to have lots of tiny tunnels. These tunnels trap as much dirt and pollution as possible.

Activated carbon filters are great at getting rid of indoor air pollutants like VOCs and ozone. They work because the bad stuff in the air sticks to the carbon. But after a while, all the sticky spots get used up, and the filter needs to be thrown away and replaced. Manufacturers usually say how long you can use their activated carbon filters. But every indoor space is different, with different sources of pollution and varying airflow from outside.

In this article, we’ll talk about what exactly is an activated carbon filter, what are the pros and cons of it and how long it will last. Without further ado, let’s get into it.

What is the activated carbon filter?

An activated carbon filter, also known as an activated charcoal filter, is a type of filtration system used to remove impurities and contaminants from air or water. It’s made from small pieces of carbon, typically derived from materials like coconut shells, wood, or coal, which are processed to make them extremely porous. These pores increase the surface area available for adsorption, which is the process where molecules adhere to the surface of the carbon.

Black grains are checked for quality. Stock footage. Close-up quality control of raw additives with professional equipment in laboratory.

When air or water passes through the filter, the contaminants in the fluid are trapped within the carbon pores, effectively removing them from the air or water. Activated carbon filters are commonly used in air purification systems, water treatment facilities, and various consumer products like water pitchers, refrigerator filters, and face masks.

They are highly effective at removing a wide range of pollutants, including volatile organic compounds (VOCs), chlorine, odours, and certain gases, making them popular for improving air and water quality in both residential and industrial settings.

What are the advantages and disadvantages of an activated carbon filter?

Activated carbon filters offer several advantages and disadvantages:


  1. Effective Removal of Contaminants: Activated carbon filters are highly effective at removing a wide range of contaminants from air and water, including volatile organic compounds (VOCs), chlorine, odours, and certain gases.
  2. Versatility: These filters can be used in various applications, including air purification systems, water treatment facilities, and consumer products like water pitchers and face masks.
  3. Improved Air and Water Quality: By removing impurities and pollutants, activated carbon filters help improve the quality of air and water, making them safer and more pleasant to breathe or consume.
  4. Safe and Environmentally Friendly: Activated carbon is a natural material, and the filtration process is chemical-free, making it safe for use and environmentally friendly.
  5. Long Lifespan: Activated carbon filters have a relatively long lifespan compared to other types of filters, especially when used in water purification systems. With proper maintenance, they can last for several months before needing replacement.
High-Efficiency Particulate Air. HEPA and Charcoal Activated Carbon Air Quality Filters Close Up. Commercial and Residential Modern Air Filtration Systems.


  1. Limited Effectiveness for Some Contaminants: While activated carbon filters are highly effective for removing many contaminants, they may not be as effective for certain substances like heavy metals, fluoride, or microbial contaminants.
  2. Regular Maintenance Required: To maintain optimal performance, activated carbon filters require regular maintenance, including periodic replacement or regeneration of the carbon media.
  3. Cost: Activated carbon filters can be more expensive upfront compared to other types of filters. Additionally, the cost of replacement cartridges or filter media can add up over time.
  4. Reduction in Flow Rate: In water filtration systems, activated carbon filters can reduce the flow rate of water due to the resistance caused by the porous structure of the carbon media.
  5. Limited Lifespan: Despite their relatively long lifespan, activated carbon filters will eventually become saturated with contaminants and need to be replaced, which can be a recurring expense.

What can an activated carbon air filter remove?

Activated carbon air filters are effective at removing a variety of pollutants and impurities from the air. Some common substances that activated carbon filters can remove include:

  1. Volatile Organic Compounds (VOCs): These are organic chemicals that can evaporate into the air and pose health risks. Examples include formaldehyde, benzene, and toluene, which can be found in paints, solvents, cleaning products, and tobacco smoke.
  2. Odours: Activated carbon filters are excellent at trapping and neutralizing unpleasant odours from sources such as cooking, pets, garbage, and chemicals.
  3. Gaseous Pollutants: They can remove gaseous pollutants like ozone, nitrogen dioxide, and sulfur dioxide, which can be present in indoor and outdoor air and contribute to respiratory problems and air pollution.
  4. Tobacco Smoke: Activated carbon filters can effectively capture and reduce the odour and harmful chemicals present in tobacco smoke.
  5. Fumes and Foul Smells: They can help eliminate fumes from cooking, paints, adhesives, and other household products, as well as foul smells from sewage, mould, and mildew.
  6. Allergens: While not their primary function, activated carbon filters may also trap some allergens like pollen and pet dander, though HEPA filters are more efficient for this purpose.

Overall, activated carbon air filters can significantly improve indoor air quality by removing a wide range of pollutants, making the air safer and more pleasant to breathe.

Residential High Efficiency Particulate Air Filters. Carbon Activated Base and HEPA. Fighting Air Pollution Inside Home.

How long can you use an activated carbon filter?

The lifespan of an activated carbon filter depends on various factors, including the type and concentration of contaminants in the air or water, the volume of fluid being filtered, the size and quality of the filter, and the frequency of use. In general, activated carbon filters will become saturated with contaminants over time and lose their effectiveness. Here are some general guidelines for the lifespan of activated carbon filters:

  1. Air Purifiers: The lifespan of activated carbon filters used in air purifiers typically ranges from 3 to 6 months under normal conditions. However, if the air is heavily polluted or contains high levels of contaminants, the filter may need to be replaced more frequently.
  2. Water Filtration Systems: The lifespan of activated carbon filters used in water filtration systems can vary widely depending on the volume of water being filtered and the concentration of contaminants. Generally, these filters may last anywhere from 6 months to 2 years before needing replacement.
  3. Masks and Respirators: The lifespan of activated carbon filters used in masks and respirators also depends on usage and environmental conditions. Manufacturers usually provide guidelines for replacement intervals, but in general, they may last anywhere from a few days to a few weeks, depending on usage and exposure to contaminants.

It’s essential to follow the manufacturer’s recommendations for replacing activated carbon filters to ensure optimal performance and maintain air or water quality. Additionally, regular maintenance, such as cleaning or replacing pre-filters or ensuring proper ventilation, can help extend the lifespan of activated carbon filters.

The key takeaway

the historical use of carbon and charcoal for filtration underscores their enduring effectiveness in improving air and water quality. From ancient Egyptian practices to modern-day applications like activated carbon filters, these materials have proven their ability to adsorb contaminants and enhance environmental health.

Activated carbon filters offer a practical solution to contemporary challenges like indoor air pollution, efficiently trapping pollutants such as volatile organic compounds (VOCs) and ozone. However, the variability of indoor environments necessitates individualized maintenance to maximize their effectiveness. While manufacturers provide replacement guidelines, factors like pollution sources and ventilation rates influence filter lifespan.

The journey of carbon and charcoal filtration, spanning millennia, highlights their ongoing relevance in addressing environmental concerns. By harnessing the power of activated carbon, we can work towards cleaner, healthier indoor environments for generations to come.

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