You want to breathe clean air in your home, so you start searching for air purifiers and their most effective filtration types. 

In one article, you stumble across a term called HEPA filtration. In another, you see true HEPA filtration. Puzzled, you click on a few more and feel as though you just opened Pandora’s box of adjectives for this type of filter—HEPA-like, HEPA, medical-grade HEPA.

You wonder, “Is there a difference between these terms? Or is it all just marketing lingo? What do I actually need?

Let’s get you some answers. 

What Makes a HEPA Filter A HEPA Filter? 

A HEPA filter, which stands for high-efficiency particulate air filter, is a type of pleated mechanical air filter that can capture a wide range of particles, including pollen and other allergens, dust, bacteria, mold spores, and even some viruses. 

This filtration technology is designed to remove microscopic particles from the air with remarkable efficiency. The concept of HEPA filtration has its roots in the Manhattan Project during World War II, where it was developed to capture radioactive particles in laboratory environments

HEPA filters are subject to stringent standards and classifications to ensure consistent performance. Understanding these standards will help you distinguish between different types of HEPA filters and their capabilities.

Definition of HEPA

A HEPA filter meets the standards set by the United States Department of Energy (DOE). To be classified as HEPA, a filter must be capable of removing at least 99.97% of airborne particles that are 0.3 microns in diameter. This means that for every 100 particles of this size that encounter the filter, only 3 will pass through.

The 0.3 micron particle size is known as the Most Penetrating Particle Size (MPPS) because it's the most difficult for filters to capture. 

The “why” behind this involves some interesting physics, namely, Brownian Motion. This principle describes the random motion of particles suspended in a medium, in this case, air. Particles less than 0.3 microns (like the size of the SARS-CoV-2 virus) exhibit more Brownian motion, which actually makes them easier to capture as they bounce around more rapidly and eventually collide with filter fibers.

On the flip side, larger particles have enough mass to get caught in between multiple filter fibers. Their bigger size makes them more likely to collide with or get trapped by filter fibers as air flows through the filter.

HEPA filters can also be incredibly efficient at capturing particles larger and smaller than 0.3 microns. 

HEPA Filter Materials 

HEPA filters can be made with a wide range of materials, including fiberglass, borosilicate glass fibers, and sometimes synthetic materials like polypropylene or polyester. 

The fibers used in HEPA filters are extremely fine and are arranged in a dense, randomly oriented mat or web, which creates a complex maze for air to pass through. This structure is what allows HEPA filters to capture particles as small as 0.3 microns with high efficiency.

Different manufacturers may use different combinations of these materials or proprietary blends to achieve specific performance characteristics. The choice of material can affect factors such as the filter's efficiency, durability, resistance to moisture and chemicals, and overall performance in different environments. 

If you’re interested, the DOE denotes several construction requirements that HEPA filters must adhere to pass muster. 

Different HEPA Classifications (H10-H14)

HEPA filters are classified into different grades based on their efficiency. The classification system ranges from H10 to H14, with higher numbers indicating better filtration performance:

These filters are commonly used in residential and light commercial applications. They provide excellent filtration for most household needs, effectively removing allergens, dust, and many other airborne particles.

These often are used in settings with the highest air quality requirements, such as hospitals, cleanrooms, and certain industrial applications. With Air Oasis, add “your home” to that list, as our iAdaptAir2.0 series has an H13 medical-grade filter. 

What HEPA Filters Can’t Do

HEPA filters are excellent at removing harmful particulates in the air. But on their own, they can’t do it all. 

These filters don’t affect volatile organic compounds (VOCs), odors, and gaseous pollutants. For that, you’ll need different technology, like carbon filters. This is important information to understand throughout your search to ensure you get the best quality possible. 

The Regulatory Bodies for HEPA Filters

Several organizations are involved in setting standards and providing certifications for HEPA filters:

• U.S. Department of Energy (DOE): Establishes the basic HEPA standard.
• Institute of Environmental Sciences and Technology (IEST): Provides detailed standards and recommended practices for HEPA filters.
• International Organization for Standardization (ISO): Offers global standards for filter testing and classification.

It's worth noting that terms like "HEPA-type" or "HEPA-like" are not regulated and may not meet the true HEPA standards. When selecting a HEPA filter, it's important to look for certifications from recognized bodies to ensure you're getting a genuine, high-performance product.

How Are These Standards Enforced?

Even though there are government-set standards for HEPA filters, the U.S. government, including agencies like the EPA, does not directly certify or register HEPA filters or air cleaning devices. In other words,there is no official government "HEPA certification" program.

While the government doesn't certify filters, independent organizations and laboratories conduct testing to verify if filters meet the HEPA standard. These include:

• Institute of Environmental Sciences and Technology (IEST)
• Underwriters Laboratories (UL)
• National Sanitation Foundation (NSF)

Ultimately, it's primarily the responsibility of manufacturers to ensure their filters meet HEPA standards and to have them tested by accredited labs. 

True HEPA Filters vs. HEPA Filters (Plus Other Common Terms)

At the end of the day, the only technically correct term for a HEPA filter is a “HEPA filter.” 

Plain and simple. 

Technically speaking, HEPA filters meet the DOE’s minimum standards of removing at least 99.97% of particles as small as 0.3 microns. 

However, marketers and manufacturers have started adding some adjectives (and other qualifiers) to help consumers make decisions about their particular product. 

Some of those qualifiers are helpful whereas others are a bit confusing.

Let’s unscramble these words:

All of this can start to feel like alphabet soup—we get it. 

Here’s what to think about when evaluating HEPA filters:

• Does it meet the minimum DOE criteria to remove at least 99.97% of particles as small as 0.3 microns? 
• Does it have a specific HEPA efficiency grade (H12, H13, etc.) listed? 
• Does the brand offer access to independent tests they’ve done to ensure they meet these requirements? 

The Benefits Of Multi-Stage Filtration Technology

HEPA filters are integral for effective air purification, but they can only do so much on their own. At Air Oasis, we employ a comprehensive 5-layer filtration system. This advanced approach to air purification goes beyond standard HEPA filtration to address a wide range of air quality concerns.

1. HEPA Filters: Our Medical-Grade H13 HEPA Particle Filter exceeds the standards by being able to capture particles as small as 0.05 microns. 
2. Carbon Filtration: In addition to HEPA, Air Oasis purifiers include activated carbon filters. These are especially effective at removing odors, volatile organic compounds (VOCs), and other gaseous pollutants.
3. Silver Microbial Filter: This filter likely uses silver's natural antimicrobial properties to further reduce bacteria and mold spores.
4. UV Light: Air Oasis incorporates UV light technology, which can help neutralize certain airborne pathogens that find their way into the air purifier.
5. Bi-Polar Ionization: This technology helps to actively clean the air by creating positive and negative ions that can neutralize harmful substances without producing harmful ozone. 

The world of HEPA filtration naming conventions can be challenging for consumers. Now you know what the HEPA standards are, the steps you can take to check a filter’s effectiveness, and the benefits of combining HEPA filters with other technologies for cleaner, fresher air.