The first HEPA air filters were used during WWII to help protect soldiers from chemicals and smoke. While those early versions little resemble what consumers buy today, it was the start of a transformation in how we sought to control air quality.
Today, filters labeled as high efficiency particulate air (HEPA) must meet specific filtration and quality standards set by the Office of Environment, Health, Safety & Security at the United States Department of Energy.
To meet these standards, HEPA air filters use layers of glass fibers that create sufficient depth to capture 99.7% of particles that are 0.3 microns in size. For a comparison, the average size of bacteria is 2 microns, red blood cells are 5 microns across, and a human hair is up to 200 microns.
A Filter Born Out Of Chemical Warfare
The development of high efficiency particulate filtration began during WWII when British soldiers sent gas masks obtained from German gas mask to the U.S. Army Chemical Warfare Service Laboratories.
At the time, the Germans were using a filter paper made of asbestos dispersed in esparto grass (a plant native to Spain and Algeria.) This method was found to be effective for many reasons. First, it trapped particles while still allowing enough air flow to the wearer. Second, the filter wouldn’t plug as a result of contact with oil-type smokes. This was considered to be a significant development in filtration technology.
After the war, development continued within the nuclear industry. The need for a material that could withstand temperatures of 2,000 degrees Fahrenheit and could treat gasses emitted from nuclear reactors resulted in the switch from asbestos and plant material to an all fiberglass construction.
Standards for HEPA air filter production, quality assurance, shipping, and hygienic use in a variety of applications came later to address issues during manufacturing, transportation, and misuse that led to filters that failed to meet requirements for health and safety in the aerospace, medical, and circuit fabrication industries.
HEPA Air Filters For The Home
The development of HEPA has seen the shift from protecting people during chemical attacks to safety from radioactive elements, and now it is readily available to consumers in a range of products.
Given its history, if you want the ultimate filter for your home, you should use a HEPA air filter. So what products use HEPA filters?
The most common use of this filtration technology includes vacuum cleaner filters, HEPA air purifiers and air cleaners. Don’t expect to find HEPA air filters in your heating and cooling system. Unfortunately, unless you have an industrial blower fan like you would find at a hospital, these filters restrict too much air flow.
Think of using a HEPA air filter in combination with the air filter you already use in your heating and cooling system. For example, when running an air purifier, you can move the device to areas of the home where people need additional relief from smaller particles.
True HEPA Filters Versus ‘Almost’ HEPA
“True” HEPA air filters meet all standards for filtration as required by the U.S. DOE. In the market today, consumers may find terminology like “HEPA-like” or “99% HEPA,” which means the filter has not undergone laboratory testing to satisfy particle reduction standards and may not perform as expected.
Also of note, HEPA is not recommended to filter volatile organic compounds, chemical vapors, odors from pets or other gas molecules.
- To deal with smells around the home, click here to read how activated carbon air filters help reduce odors
With the right filters in your home you help to improve indoor air quality and reduce the chances of suffering from allergies. Shop CleanerFilters.com to replace your air filters today!
Have you used HEPA filters in your home? Let us know in the comments below!