Cutting through carbon filter confusion
Can charcoal really clean the air?
If you’ve been shopping for an air purifier, you may have noticed the many different types of filters each system uses, adding to the decisions you need to make.
There are pre-filters, stainless pre-filters and washable pre-filters. There are six different types of HEPA filters, based on their efficiency ratings. Adding to that, you may hear about charcoal filters, carbon filters and activated carbon filters.
To help answer some questions you may have, this article will focus on charcoal, carbon and activated carbon filters, the differences and similarities between them and how they can play a role in increasing indoor air quality.
What is a carbon or charcoal filter?
Charcoal is a black residue that results from burning wood or other materials. It contains a high concentration of carbon, which is why you might hear filters referred to as “carbon’ or “charcoal” filters in the same way.
But how could this black residue possibly be related to cleanliness? The fact is charcoal has been used as cleaning agent for centuries. The Romans actually combined fragments of shells, bones and bark with charcoal powder to make a cleansing toothpaste.1 (1 Colgate, The Evolution of Charcoal.)
Today, “activated” carbon or charcoal filters are chosen for their cleansing capabilities and are commonly used in water and air filtration systems.
What is an activated carbon filter?
Activated carbon is charcoal that is processed in a way to make it extremely porous.2 (2New World Encyclopedia, Activated Carbon.) The increases its absorption power, which can make it an ideal material for attracting pollutants in the air.
A good way to think about the absorption properties of charcoal is to consider its use in the ER to absorb and deactivate drugs or other harmful substances in the stomach.3 (3Activated Charcoal, An Effective Treatment for Poisoning, National Capital Poison Center.)
Now, apply that same example to an activated carbon filter in an air purifier, with air being the pollutant ingested. As air is “consumed” by your air purifier, the activated carbon filter is designed to capture and deactivate pollutants, such as odors and VOCs, much like charcoal deactivates pollutants in the stomach.
What is a VOC?
While everyone knows what an odor is—whether caused by your pets, your trash, dirty laundry or even your cooking—there can be many odorous chemicals in your home whose source may not be that obvious.
For example, a VOC, or volatile organic compound can be in the home or office environment. These chemical contaminants can be released into the air from a range of origins.
Sources of Volatile Organic Compounds4
- Caulks, sealants, adhesives
- Paints, varnishes, stains, wall coverings
- Carpeting, vinyl flooring
- Fabric materials, furnishings
- Cleaning agents, air fresheners
- Personal products, like perfumes and shampoos
- 4CDC, Indoor Environment Air Quality: Chemicals and Odors.
Part of a multi-staged filtration system
Many air purifiers have external filters to catch larger particles, along with HEPA filters to catch much smaller particles, like bacteria, viruses and mold, as well as pollen, pet hair and dander. But, when it comes to airborne odors and chemicals, that’s the job of the activated carbon filter. Learn more about its air cleaning capabilities.
