The Science Behind HEPA Filters: Why Regular Replacement Is Critical

If you regularly work with lab equipment, like a biosafety cabinet or fume hood, then you know the importance of HEPA filtration. When you’re dealing with potentially noxious or hazardous contaminants, you want to be assured that ventilation is functioning properly and that filters are in good working order. But what exactly are the filters doing? Why is regular replacement vital? We’re here to answer these and other questions.

What Is A HEPA Filter?

As is true with many modern technologies, High-Efficiency Particulate Air (HEPA) filters were first used by the military. They were conceived of and used in the 1940s during World War II. While air purifiers and filters had been in use since the middle of the 19th century, this new product offered an innovation in the materials used and results achieved. First called the “absolute filter,” this vital filtration material has been known as a HEPA filter from the 1960s onward.

Since HEPA filters were known to catch even the tiniest airborne particles (at least 99.97% of particles that are 0.3 microns in diameter), they began to be used in commercial products and also across various industries. Now, they are also known to be vital components of lab equipment that help to maintain a sterile and safe working environment. Lab workers depend on proper filtration to ensure that they are not at risk of inhaling potentially harmful substances.

In order to ensure that particulate matter is removed from the air, HEPA filters utilize tightly interwoven glass and synthetic fibers. Together, these fibers form a maze-like structure that traps and holds particles. The HEPA filtration process utilizes three primary mechanisms: interception, impaction, and diffusion.

With interception, mid-sized particles simply stick to fibers that they come into contact with when passing through the filter. When particles greater than 1 micron in size enter a filter and collide with the fibers, they then embed themselves in a process called impaction. Diffusion helps to capture the very smallest of particles during their erratic movements as they connect with and then stick to fibers in the HEPA filter. The random arrangement of fibers into a dense mat within the filtration material helps to ensure that all particles that enter are captured.

Due to the serious nature of their efficacy, HEPA filters are highly regulated and undergo strict certification. The filters used in laboratory settings are engineered to a higher standard than those that are commonly used in consumer and household appliances, and are able to filter to a smaller particle, vital to the safety of the workers using lab equipment.

Why Do HEPA Filters Need Regular Replacement?

HEPA filters are built to remove a wide array of sizes of particles from the air. After doing that for some time, the filter material can become saturated with particles and begin to lose its effectiveness. Particles may begin to slip through if the filter material can no longer catch them. Because they can no longer trap and hold potentially harmful particles, these particles are then free to travel through the air, threatening the well-being of workers using the lab equipment. Once HEPA filters used in biosafety cabinets are compromised, they need to be replaced.

Apart from a high airborne contaminant load, there are other factors that impact the lifespan of HVAC filters: excessive humidity or moisture, increased lab activity and workload, types of chemicals and substances being worked with, and process intensity. When all of these factors coincide, a HEPA filter may require replacement at an even higher frequency than the manufacturer recommends under ideal conditions.

When filters are not changed regularly, a laboratory risks respiratory irritation or chemical exposure, compromised lab equipment performance, lab equipment breakdown, failed experiments, delayed research, and wasted resources. It is also possible that neglecting to change HEPA filters could lead to regulatory non-compliance, which could cause serious reputational harm or financial strain. Clearly, though changing filters could sound like a simple task, it isn’t something to put off–effective HEPA filters are at the center of effective lab equipment, full stop.

It’s important for each laboratory to establish a HEPA filter replacement schedule based on its unique circumstances. The experienced technicians at DigeLab Solutions can help you to build a customized maintenance schedule based on both the manufacturer’s requirements and lab equipment monitoring.

When Is It Time To Change HEPA Filters?

Firstly, it’s a good idea to reference the manufacturer’s timing recommendations. Under typical use, HEPA can last anywhere from 3-5 years. That said, keep an eye out for obvious signs that a filter is no longer functioning optimally. These could include:

• Decreased airflow
• Higher resistance
• Noticeable odor
• Visual changes
• Increased particle counts
• Noticeable accumulation of dust
• Increase in energy consumption

Any or all of these signs could point to a need for service, and likely, filter replacement.

Next, work with a certified professional who can manage your lab equipment maintenance needs. Could you just save time and change the filter yourself? This is not recommended, as any time a filter is replaced, a unit needs to be recertified by an approved professional to remain compliant. DigeLab Solutions can handle any and all of your HEPA filter needs and can also handle biosafety cabinet certification and fume hood repair when your lab equipment is acting up.

Work With DigeLab Solutions for Lab Equipment Maintenance

If it has been several years since a HEPA filter was replaced and you’re noticing other key indicators, contact the team at DigeLab Solutions, and we can schedule maintenance on your lab equipment. Apart from changing HEPA filters, we can also make repairs and upgrades, perform routine maintenance tasks, and offer documentation, biosafety cabinet certification, and fume hood repair. When your lab equipment starts to become problematic, you don’t have time to wait–contact DigeLab Solutions for help today!