Do HEPA Filters Have Fiberglass In Them?

  • Author: Irene Mills
  • Date: September 26, 2022
  • Time to read: 5 min.
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Touching or breathing in fiberglass isn’t a pleasant experience. 

As a result, a lot of people get somewhat confused when they hear that HEPA filters may have fiberglass in them. 

After all, HEPA filters are designed to keep the air that we breathe as pure as possible. 

How could that possibly work when the central part of the filter is made from something that you don’t want to be breathing in?

So, is it true?

Do these filters that are meant to protect us really have one of the last things that we want to be breathing in?

In this article, I will be answering the question ‘Do HEPA filters have fiberglass in them?’ 

As well as, give you a little bit of an idea about how they work, and whether there are any alternatives available.

Do HEPA Filters Have Fiberglass In Them?

Most of the HEPA filters that you find for sale will be fiberglass filters. 

This is because fiberglass is the most affordable material for making filters. 

Some would say that it is also the most effective, although the jury is still out on that one. 

Only 3M is making anything other than fiberglass HEPA filters at the moment, and they will likely be the only company doing so for the foreseeable future.

However, don’t worry. There is nothing dangerous about fiberglass HEPA filters. 

As long as you are not cutting them up and sticking them on your face to make a mask, then you do not have to worry about breathing in fiberglass. 

The material isn’t just going to break down. If you put fiberglass filters in your air purifying system, you aren’t suddenly going to have a ton of glass fibers floating around your home.

What Are HEPA Filters Made Of?

It is always important to check the label of the product to see what type of HEPA filter you have been purchased.

We are going to put aside the cloth and plastic that generally covers the HEPA filter.

Instead, we want to focus on the main filter part i.e. the part that is doing the hard work in keeping that air clean.

In almost all cases, these filter part is going to be made from a material known as fiberglass. Fiberglass is one of the most effective filters imaginable. 

You can think of fiberglass as a cloth constructed glass. We will talk a little bit more about that soon.

In recent years, we have started to see HEPA filters made of plastic. 

Specifically, these are a combination of polypropylene and polyolefin plastic. 

These materials are woven together much in the same way that fiberglass filters are woven together.

You have to remember that the definition of a HEPA filter is quite strict. In the United States, 99.97% of all particles above a certain size. 

This means anything bigger than 0.3 micrometers. So, HEPA filters have to remove some pretty small particles.

There are not that many materials that would be able to filter like this. 

In fact, up until recently, the only fiberglass would do the job. It is only in recent years that we have started to see those plastic alternatives. 

are hepa filters made of fiberglass

Do HEPA Filters Contain Glass?

Sort of. You won’t find any glass shards mixed up into the filter, though.

Fiberglass is created when glass (much like what you have in your windows) is heated up to an incredibly high temperature. 

Once the glass has been heated up, this liquid is forced through a series of holes. These holes are tiny. 

This creates a ton of what are, essentially, glass threads.

Once these glass threads cool down, they can be woven together to create a variety of different items, one of which could be a HEPA filter.

So, yes. Fiberglass HEPA filters will contain glass, but it is going to be a very, very changed form of that glass.

Why Are HEPA Filters Pleated?

If you looked at a HEPA filter ‘up close’ that you will see that it is pleated, which means that it is arranged in a zig-zag pattern. 

When something is arranged in a zig-zag pattern like this, it has more surface area. 

When a HEPA filter has more surface area, it can filter more air at the same time.

 With That ‘being said, pleating’ makes the HEPA filter much more effective.

Do Filtrete Filters Have Fiberglass?

Filtrete filters do not contain any Fiberglass. These filters, instead, contain a mixture of polypropylene and polyolefin plastic. 

This pretty much means that these filters have a plastic filter.

Filtrete filters will still work in the same way as fiberglass filters, though. 

They will capture any of those tiny particles that try to get through the filter. By capturing these particles, your air is purified.

Filtrete filters are no more and no less effective than fiberglass. 

Although, some may say that they have a lot more advantages, notably the fact that they can last a lot longer before they need to be changed. And, believe us, you will want to change fiberglass HEPA filters regularly. 

You do not want them to just breakdown. That is when you will start having issues.

Which HEPA Filters Have No Fiberglass?

Most HEPA filters are made from fiberglass. This is because fiberglass is one of the most effective materials for even the smallest of particles from the air. 

Filters can be made from a variety of different materials.

But because HEPA has a specific definition, very few of them will be glassed as HEPA filters.

The only non-fiberglass product classed as a HEPA filter is the FIltrete range of products from 3M. 

Final Thoughts – Do HEPA Filters Contain Fiberglass?

Do HEPA filters have fiberglass in them?’ 

Nearly all HEPA filters will contain fiberglass. This is the only way to ensure that they can filter all particles from the air. 

If you want something that does not contain fiberglass while is still classed as a HEPA filter, then you will need to buy Filtrete. 

These products are only sold by 3M and contain a plastic that helps to filter the air particles instead.

Looking For Air Purifier Guides?

If you’re looking for more air purifier resources, consider checking out our other posts on air purifiers.

irene mills author of freshairdevices

(writer & chief editor)

Irene Mills is eager to help others create an indoor allergen-free home. She has years of experience testing out air purifiers, dehumidifiers, and other products designed to help with indoor air quality. Learn more about me.