Published on:

Is Insulation Toxic? Can it be a Health Hazard?

We’ve all heard horror stories about home insulation being a health hazard. But most of these hazards are easily preventable.

Plus, the benefits of insulating your home greatly outweighs the probability of developing a respiratory issue.

Here’s the 411 on insulating houses. You’d be surprised to know that the road to a safe and comfy house is just three steps away.

Why Do You Need Insulation in the First Place?

home insulation work

Added Comfort

Aside from it being a requirement of most housing codes, a properly insulated home provides more comfort. Insulation works by slowing down how heat moves through objects (conductive heat flow) and how heat moves through the air (convective heat flow). This, in turn, helps maintain a constant indoor temperature compared to the outdoors, which keeps your home cool in the summer and warm in the winter.

Saves Energy

Adding insulation to your home doesn’t only make it a more comfortable place to live. The most important role of insulation is to save energy (1). Insulation works by slowing down heat flow through materials and the air within the insulated space.

EPA estimates that homeowners can save an average of 15% on heating and cooling costs (or an average of 11% on total energy costs) by air sealing their homes and adding insulation in attics, floors over crawl spaces and basements.

Insulation alone doesn’t help reduce your energy bills. This has to be coupled with proper sealing. Think of it like turning on the air conditioning but leaving the door open. It sounds drastic, but if you add up all the small gaps in your home, it may well possibly equate to leaving a window open.

Proper ventilation also helps keep the home energy efficient because it allows the air to circulate through the proper channels. Ventilation keeps the air fresh and prevents moisture from accumulating in certain spots which may eventually lead to a mold problem.

Lessens Noise

Insulation also acts as a noise barrier. This is especially beneficial if you live next to a busy street, as the insulation reduces the noise coming from outside. If you live in an apartment or attached townhouse, it prevents your neighbors from eavesdropping.

Choose Your Insulation Wisely

Keep in mind that the amount of energy you save depends on other factors like the type of insulation you use, environment conditions and proper installation (2). That said, you may need to use a combination of insulation materials for different parts of the house.

Cellulose Insulation

cellulose home insulation

Choosing cellulose material is the safest way to go in terms of health considerations. This material is organic, made of recycled cotton, paper, cork, etc. Cellulose insulation is commonly applied in walls of the main floors.


This material easily fills cavities compared to other materials that need to be shaped and wrapped around electricals. Since the materials used are all organic, it poses the least health hazard among all other insulating options.

Hazards and Precautions

The downside of this type of insulation is that it can be a fire hazard and emit an ammonia-odor. Aside from adding moisture barriers, you may also want to consider treating the material with a fire-retardant chemical (3). This slightly reduces its insulating capabilities, but it’s a good trade off if you don’t need as much insulation in the first place.

Certain treatments of cellulose-based materials can emit vapors that can lower the insulated space’s air quality. That said, a properly treated and installed cellulose insulation will not only keep your house comfortable, but also safe from toxic chemicals and fires.

Mineral Insulation

mineral wool insulation piece

Mineral insulation The most common examples of these materials are Fiberglass and mineral wool. These materials are generally used to insulate buildings with heating systems.


Builders use mineral insulating materials because they are fire-proof and don’t absorb moisture (4).

Mineral insulation generally is rot-proof, vermin-proof, and low in combustibility.

Fiberglass is relatively inexpensive and, unlike cellulose sprays, it lasts longer and won’t lose its form. This means that it has higher insulating capabilities. Mineral wool is another example of  Mineral insulation. It provides good thermal conductivity, which means your home can regulate temperatures more efficiently. Aside from that, mineral wool provides better protection against noise pollution compared to fiberglass.

Hazards and Precautions

Fiberglass is made up of raw silicon dioxide fibers and oxides of aluminum and other elements. They come together as fine fibers that when exposed, can cause hazards ranging from mild skin irritation to severe respiratory issues and even cancer (5). Installers should wear long sleeved shirts and long-legged pants with gloves, a face mask and eye protection. Properly sealing and installing fiberglass will eliminate these hazards, leaving you with a safe and well-insulated home.

You can also learn more about the dangers of this material from this video:

One of the most notorious mineral insulating materials used in old houses is asbestos. This material has since been discontinued for use in buildings because of its cancer-causing effects. This material easily crumbles and can spread microscopic particles into the air. These are easily inhaled and have been known to cause lung and larynx cancers.

We get it, old houses have a certain charm that you can’t get with a new construction. But if you’re looking to remodel a house built in the 1980s or earlier, make sure you have it inspected for asbestos and retrofitted with a safer insulating material.

Spray Polyurethane Foam (SPF) and Polystyrene

spray polyurethane foam for roof

Spray Polyurethane Foam and Polystyrene insulating materials fall under the plasticized insulation category. They are usually sprayed onto cavities and allowed to cure. Polyurethane foam is best applied on crawl spaces and other areas that is not vented and has high moisture– basically, it has a wider application range than the other materials we mentioned


Plastic foam insulation does not decay easily and is also not a target for vermin. It’s one of the easiest insulating materials to apply. That said, a lot of homeowners that do DIY renovations, prefer this material over others that need more work to handle.

Hazards and Precautions

Plasticized insulating materials are known to release toxic vapors when not cured properly. This can cause eye irritation. Luckily, this is easily prevented by wearing protective gear while installing and waiting for the proper curing time to pass. It’s better to go over the recommended curing time to ensure proper settling of the foam material.

Other health hazards of installing SPF and Polystyrene are respiratory irritation and neurological effects (6).

SPF contains Isocyanates, which have been reported to be the leading attributable chemical cause of work-related asthma

Proper respiratory protection and protective equipment will greatly help in preventing these health hazards from affecting workers.

See how it looks like and learn more in this video:

Final Thoughts

Yes, insulation can cause a lot of health hazards. But these hazards can be eliminated with 3 easy steps: choosing the appropriate insulating material, considering how this material interacts with its surroundings, and proper installation. To make it even easier and safer, you can have the insulation professionally installed. If you consider these three important factors, you can rest easy knowing that your insulated house is not a health hazard. Plus, you can reap the rewards of saving loads of money from your energy bill!

  1. Why Seal and Heat. Retrieved from:
  2. Insulation And Your Home: Health Considerations. Retrieved from:
  3. Cellulose Insulation- A Smart Choice. Retrieved from:
  4. nsulation and Fire Hazards in the Construction Industry. Retrieved from:
  5. Certain Glass Wool Fibers (Inhalable). Retrieved from:
  6. Green Job Hazards. Retrieved from:,when%20working%20with%20fiberglass%20insulation.