Fiberglass insulation is the most common home insulation in the U.S.
Insulation is generally safe when it’s properly installed
Damaged, exposed, or old insulation can pose health risks
Asbestos insulation (or contaminated vermiculite) is carcinogenic
Direct insulation exposure may cause skin and respiratory issues
You may have noticed some pink pillowy material shoved into the corners of your unfinished attic. That’s fiberglass insulation, the most popular type in America. Fiberglass insulation is found in 71% of U.S. homes and comes in many forms—whether it’s batt, blown-in, or loose insulation. It may keep your home warm, but is insulation dangerous?
As it turns out, insulation can sometimes be hazardous. It’s not just fiberglass insulation (or the dreaded asbestos) that poses a risk. Luckily, most types of insulation are only dangerous when they’re not properly installed, damaged, or exposed. In other words, you can successfully keep your pipes toasty and your family safe. Here are some common insulation health hazards—and what you can do about it.
1. Cancer Risk
The main way insulation poses a health risk is when the tiny, needle-like fibers become airborne. Most often, you’ll see this happen with loose fill insulation, exposed blanket batts and rolls, or damaged blown-in insulation. Inhaled fibers can lead to health issues, including cancer. Not every type is cancerous, but some pose a greater risk than others.
Asbestos Insulation Is a Known Carcinogen
Until its international ban in 1979, asbestos material was commonly used in everything from attic insulation and crawl space insulation to vinyl floor tiles and roofing. According to the National Cancer Institute (NIH), asbestos exposure can cause:
Mesothelioma (a relatively rare type of cancer that affects the thin membranes that line the chest and abdomen)
Friable asbestos is the most dangerous. This means that you can easily crumble it in your hands, releasing microscopic asbestos fibers. That’s part of what makes asbestos insulation removal so tricky—and it should only be done by a professional.
Research Is Mixed for Fiberglass or Mineral Wool Insulation
After the era of asbestos, other types of insulation like mineral wool insulation and fiberglass insulation rose in popularity. Though some studies have shown that these materials may be carcinogenic when inhaled, research is mixed.
These types of insulations are commonly made of:
In 2002, the International Agency for Research on Cancer (IARC) downgraded the classification of these materials from Group 2 (a probable human carcinogen) to Group 3 (unclassifiable). In other words, there’s not enough evidence to prove they cause cancer in humans, but there’s not enough evidence to prove that they don’t.
The Environmental Protection Agency (EPA) still lists refractory ceramic fibers as probable human carcinogens, but ceramic insulation is generally only used as pipe insulation in commercial settings where pipes are exposed to extreme heat.
2. Vermiculite Insulation Asbestos Contamination
Vermiculite insulation has become synonymous with asbestos, but that’s a misnomer. In its pure form, vermiculite is safe. The problem is that it’s often contaminated with asbestos, especially if it was manufactured in Libby, Montana.
While you won't find vermiculite in new insulation, the U.S. Geological Survey (USGS) estimates that 1 million homes in the United States still have vermiculite insulation. This type of attic insulation is one of the most common asbestos products, so it’s important to test your attic insulation if you have an older home.
3. Skin Irritation and Respiratory Issues
Anyone who’s ever accidentally touched fiberglass insulation knows that it can instantly irritate skin. Hello, contact dermatitis—but insulation exposure goes beyond red, itchy hands. The tiny fibers that make up insulation material can also irritate your eyes, nose, and throat.
You might find yourself:
If you’ve got respiratory problems like asthma, high levels of fiberglass exposure from insulation may exacerbate your symptoms and be dangerous to your health.
4. Harmful Chemicals From Spray Foam Insulation
Spray foam insulation, which is usually made from polyurethane, makes for an easy DIY—but you have to install it properly.
According to the EPA, spray foam insulation may off-gas harmful isocyanate vapors and aerosols when it’s first applied or damaged.
This can lead to nasty symptoms like:
Shortness of breath
Tightness in chest
It’s also possible to develop an allergy after exposure in a process called sensitization. There are cases where workers who are regularly exposed to SPF insulation develop asthma.
How Can You Protect Your Home From Insulation Health Hazards?
Insulation is usually not dangerous as long as it’s not damaged and properly installed. In fact, it can last decades and usually won’t cause any health problems unless you’re handling it directly without personal protective equipment. Nonetheless, there are some things you can do to avoid the potential health risks.
Test for Harmful Insulation
If you have an older home or vermiculite insulation, it’s worth having a professional test your home’s insulation for asbestos. Learn the common places asbestos lurks in homes (like walls and flooring) and the asbestos warning signs (like if your house was built before 1980).
Remove or Encapsulate Your Asbestos Insulation
Do not attempt asbestos wall or attic insulation removal on your own. The best way to protect your family is to hire an asbestos removal service to remove it. Sometimes insulation removal isn’t actually the safest option, and encapsulation will create an air-tight seal around the asbestos so it can’t be inhaled.
Repair or Remove Damaged or Old Insulation
Even if insulation isn’t damaged, it can start to deteriorate after 10 or 15 years. As it flakes, the inhalation risk grows. Have your old insulation inspected, and if need be, opt for an insulation replacement from a home insulation contractor.
You can use a checklist for inspecting and repairing your own insulation to make sure you’ve got all your bases covered.
Cover Exposed Fiberglass Insulation
When does exposed fiberglass insulation matter? Not often. It’s only an issue if it’s:
In a room you frequent
In an area exposed to moisture (since wet insulation harbors mold and loses effectiveness).
Hire an insulation contractor to cover exposed insulation in high-traffic areas. You may want to replace your existing insulation with faced insulation or rigid foam insulation if it’s regularly exposed to moisture.
Let Spray Foam Insulation Cure
Wear personal protective equipment (like a mask, goggles, and gloves) while applying spray foam, and allow it to cure to avoid potentially hazardous off-gassing. According to the EPA, foam insulation generally needs eight to 24 hours to cure, but every manufacturer has different instructions.
Choose a Safer Type of Insulation
If you’re installing new insulation or renovating an insulated area, a safer type of insulation may be the best insulation for your home. Cellulose insulation is an eco-friendly option made from recycled materials.
It’s often used as an alternative to blown-in fiberglass insulation. Some brands have non-toxic lines of mineral wool and fiberglass insulation that are free from formaldehyde and other additives.