HEPA Filter Integrity Testing

HEPA filters are a critical component of many pharmaceutical medical device and clean room processes. They’re used to remove contaminants from air streams and protect workers, patients and products, but they also need to be replaced on a regular basis.

A HEPA filter integrity test is one way to determine when it’s time for a replacement. The need for pharmaceutical and medical facilities to have effective filtration systems is paramount. This is especially true when dealing with sensitive products or processes that must be protected from outside contaminants. Unfortunately, even the best filtration systems can eventually become outdated or damaged over time and will need to be replaced before they can sustainably protect your product. In order to determine when it’s time for a replacement, you’ll need to perform a HEPA filter integrity test.

The following guide will walk you through this process and explain what it means for your filtration system.

What is a HEPA Filter Integrity Test?

A HEPA filter integrity test is a simple procedure that can be performed to determine if the filters in your filtration system are performing their job properly. It involves placing a sample of air through the system and measuring its particle count before and after it passes through the filters. There should be difference between the two counts as the filter should be removing the particles, if there isn’t, then it means that the filters need to be replaced. The measurement of particle count is usually done in units of particles per cubic metre (pcm) or microns (µm). An air sample will be taken from your facility and analysed using an aerosol particle counter.

Types and grades of HEPA filter.

HEPA filters come in various grades: EPA, HEPA and ULPA type. The difference between them is how fine the filter can remove particles from the air. A typical HEPA filter can remove particles as small as 0.3 microns, while a ULPA filter can remove particles as small as 0.1 micron or even less.

When should you test you HEPA filters?

The frequency of HEPA filter testing depends on the environment your facility is in. If it’s a clean environment, you may want to test every 6 months or even once a year. In fact, many companies that manufacture and sell HEPA filters recommend testing them at least once every year. If you see an increase in the pressure differential across the filter, this also could be an indication that you need to check, test, or change your HEPA filters.

How do you test a HEPA filter?

The best way to test a HEPA filter is by using an air sampling instrument usually a photometer. This is done by introducing particles before the filter using an aerosol generator and then taking a sample of the air that goes through the filters and measuring how many particles are in it. You can then compare the number of particles from before and after you installed your new HEPA filter to see if it’s working properly. If you have more than one type of filters, such as both ULPA and HEPA, then the test criteria will be different.

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