Is Attic Insulation Safe to Breathe?

You might have heard that insulation can be hazardous to your health. Insulation these days is not as toxic as it used to be, but that does not mean it is entirely safe. It’s particularly unsafe when you breathe it in.

Breathing attic insulation poses various health hazards, especially if the insulation is old. The insulation used in the past contained formaldehyde, a likely carcinogen (cancer-causing agent). Modern-day insulation can irritate and damage the lungs. 

This article examines the health risks posed by insulation so that you can make the most informed decision to protect yourself and your family.

insulation of attic with foam

What Is Insulation?

You might have heard the word insulation used countless times without stopping to think about what it actually is.

Insulation is a unique material designed to slow or prevent heat flow into or out of a dwelling. This material is placed between walls and ceilings to keep a home warm in winter and cool in summer. 

Homeowners would spend a lot more on heating and cooling costs without insulation. This means that insulation typically pays for itself.

There are various types of attic insulation. Fiberglass insulation is the most common type in houses since it is highly effective and easy for builders to install. This form of insulation is considered safer than some other options homeowners might choose, but it can still be risky.

Why Is Attic Insulation Bad to Breathe?

foam attic insulation

Fiberglass is a material that looks innocent enough—it even resembles cotton candy, a fun and delicious treat. However, the material isn’t made of innocuous sugar—it actually contains small glass or silica fibers, hence the name “fiberglass.”

Resin binders are also used to make the insulation thicker, making it more effective at preventing heat loss. When these tiny particles are breathed in, they can and do cause health issues.

Years ago, manufacturers used formaldehyde as a binder in insulation material. The International Agency for Research on Cancer (IARC) classifies formaldehyde as a Group I carcinogen, meaning that it can cause lung cancer or other cancers like leukemia. 

Although many experts claim that there is no definitive proof that this organic compound causes cancer.

However, contact with formaldehyde is known to cause other less severe conditions such as allergic reactions, skin irritation, and respiratory difficulties when it is breathed in. 

On top of that, people who work on old houses can still come into direct contact with fiberglass insulation that contains formaldehyde and easily inhale the fibers.

Resin binders in fiberglass insulation contain styrene. Styrene can lead to the devastating lung disease bronchiolitis obliterans when breathed in. Although this disease is not common, it does occur with extreme exposure. 

It is also worth noting that different fibers can either be inhalable or respirable. The section below details the differences between these two terms.

Inhalable vs Respirable

fiberglass insulation in the attic

When a particle enters the upper respiratory system, it is considered respirable. When such a particle enters the lungs, it is said to be inhalable. Because of their minute size, fiberglass attic insulation particles are both inhalable and respirable.

Fiberglass fibers vary in size. The longer they are, the more likely they are to get into someone’s lungs. Knowing this to be the case, manufacturers intentionally break up fiberglass fibers to shorten them, making them less dangerous to the lungs when breathed in.

However, this is not a foolproof process. A percentage of fibers do end up being long enough to harm the lungs when inhaled.

Furthermore, these fibers of glass are biopersistent, meaning they persist—or do not quickly dissolve—in the lungs as biosoluble fibers do. The longer these types of glass fibers stay in the lungs, the more damage they cause. 

The North American Insulation Manufacturers Association (“NAIMA”) claims that fiberglass insulation is perfectly safe and only a small percentage of glass fibers are biopersistent. But even a small amount of biopersistent glass fibers can become disastrous.

Symptoms of Breathing Attic Insulation

It’s imperative to know the symptoms of excessive fiberglass particle exposure. This is especially true for professionals or DIYers who come into contact with attic insulation on a regular basis.

Initial signs can include throat, mouth, nasal, and lung irritation. This irritation can lead to severe coughing and even a nosebleed. Long-term consequences include the development of asthma or other lung disorders.

Long-term problems are more common in people who regularly work with this type of insulation. The more time you spend around it, the higher the risk. If you already have asthma or bronchitis, the condition can worsen significantly after inhaling attic insulation.

What to Do if You Inhale Attic Insulation

fiberglass insulation

If, after having direct contact with attic insulation, you begin to feel irritation in your throat, mouth, or nose, you have probably inhaled insulation particles. You might also develop a sudden headache or get a rash on skin exposed to the product.

Here are the most important steps to follow after exposure:

Get Out Immediately

Once you realize that you have inhaled attic insulation, get out of the attic right away to prevent further exposure. 

Seek Medical Attention

Often, people do not seek medical attention after inhaling attic insulation. However, it is essential to get a physician’s advice so that they can help you minimize the damage caused by the exposure.

Look Out for Symptoms

If you’ve had a lot of exposure to fiberglass insulation, be sure to watch out for symptoms of lung problems such as coughing and wheezing. As always, seek medical care if you feel that something is wrong. 


Despite what the insulation industry says, attic insulation is not truly safe to breathe in. Exposure can cause health effects like lung, nose, and skin irritation. Therefore, you should wear a respirator or mask and gloves when handling the material.

If you believe that you have inhaled attic insulation, the best thing to do is to walk away and get to a clinic or hospital for further guidance.