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Is Insulation Dangerous?

Insulation is an indispensable component in the construction of buildings, playing a crucial role in maintaining the thermal comfort of our homes and offices. However, in recent years, concerns have emerged regarding the potential health risks associated with certain types of insulation. So, is insulation dangerous? The answer isn’t a straightforward ‘yes’ or ‘no’. It depends on the type of insulation used and how it is installed and handled.

Let’s delve into the matter by focusing on how specific types of insulation can pose risks. In contrast, others like mineral wool, phenolic insulation, and Expanded Polystyrene (EPS) maintain a relatively high safety standard.

Which insulation is dangerous?

Asbestos Insulation: The Silent Health Threat

Asbestos, a group of naturally occurring silicate minerals with high heat resistance and tensile strength, was once celebrated as a “miracle mineral” and widely used in construction and insulation products throughout the 20th century. Its fire-resistant and insulating properties made it an ideal material for insulating pipes, attics, walls, and around heating ducts.

However, when disturbed, asbestos materials can release microscopic fibres into the air. If inhaled, these fibres can become lodged in the lungs, leading to severe health problems over time. These include lung cancer, asbestosis, and mesothelioma (an aggressive and deadly form of cancer).

Due to these high risks, asbestos is banned in more than 60 countries, though not all. Its removal from existing buildings is a complex process that must be executed by trained professionals wearing personal protective equipment (PPE) to prevent exposure and contamination.

Asbestos Fibres
Asbestos Fibres
Urea Formaldehyde Foam Insulation (UFFI)

Urea-Formaldehyde Foam Insulation (UFFI) gained popularity in North America in the 1970s as an energy-saving option for injecting into existing homes. The foam, produced from the reaction of urea and formaldehyde, was used to insulate and air-seal walls, ceilings, and floors.

However, during installation and for some time after, UFFI can “off-gas” formaldehyde. This causes numerous health issues, including irritation of the eyes, nose, throat, and skin, asthma symptoms, and in high concentrations, potentially cancer. Exposure can also lead to more severe health effects, such as impaired lung function and allergic sensitisation.

Certain Fiberglass Insulation

Fibreglass insulation, made from extremely fine glass fibres, is commonly used for thermal insulation and sound absorption in buildings. Its popularity comes from its affordability, ease of installation, and effective insulating properties.

But the small particles that make up fibreglass insulation can pose a risk if not handled properly. If the insulation is disturbed, it can release these particles into the air. When they come into contact with the skin, or eyes, or are inhaled, they can cause irritation and itchiness.

Long-term exposure can lead to more serious health problems. For example, inhaling these fibres can lead to respiratory difficulties, and there’s ongoing research on whether prolonged fibreglass exposure can increase the risk of lung cancer.

Protective gear, such as gloves, masks, and long-sleeved clothing, should be used when installing or disturbing fibreglass insulation to prevent these health issues. Once properly installed and sealed behind a wall or other barrier where it can’t be accidentally disturbed, fibreglass insulation poses minimal health risks.

Blown Fibreglass Insulation
Blown Fibreglass Insulation

What can you do if you find exposed insulation in your home?

If you have exposed insulation in your home, the course of action to take largely depends on the type of insulation and its location. Here are some general steps you can follow:

  1. Assess the situation: Identify the type of insulation if you can. Some materials like asbestos can pose serious health risks and require professional handling. If the insulation is older (installed before 1990), it may be wise to assume it contains asbestos and handle it accordingly.
  2. Limit exposure: Prevent people, especially children and pets, from accessing the area with exposed insulation. This will limit the chance of them touching the insulation and subsequently inhaling or ingesting harmful particles.
  3. Don’t disturb the insulation: If the insulation is friable, meaning it can be crumbled or pulverised by hand pressure – as is often the case with asbestos – avoid touching it or disturbing it in any way. Disturbance can release harmful fibres into the air.
  4. Contact professionals: If the exposed insulation is or maybe asbestos, contact a licensed asbestos abatement contractor to deal with it. They have the appropriate knowledge, experience, and equipment to handle asbestos safely.
  5. Replacement or encapsulation: If the insulation is not asbestos, consider replacing or encapsulating the exposed insulation. Exposed fibreglass or cellulose insulation, for instance, can be covered with drywall or a similar material. Encapsulation involves sealing the insulation behind a protective barrier.
  6. Use personal protective equipment (PPE): If you must handle or be near the insulation, ensure you’re wearing appropriate PPE, such as gloves, a long-sleeved shirt, long pants, closed shoes, safety glasses, and a high-quality dust mask or respirator.

Which insulation is NOT dangerous?

Mineral Wool

Mineral wool, created from molten glass, stone, or industrial waste, is spun into a dense, fibrous material capable of resisting high temperatures. This property makes it an excellent fire barrier in addition to providing soundproofing. Furthermore, its unique composition allows it to breathe, reducing the risk of condensation, dampness, and the associated issues.

Because mineral wool is made from natural materials, it is non-toxic. Unlike some other forms of insulation, it doesn’t release harmful particulates or off-gas potentially hazardous substances into the air, making it a safe option for homes and commercial buildings. It’s worth noting that the handling of mineral wool requires personal protective equipment to prevent skin and eye irritation, although once installed, these risks are negated.

Phenolic Insulation

Phenolic insulation, known for its slim profile and impressive thermal performance, consists of phenol-formaldehyde resin. The phenolic foam is blown into a closed-cell structure, resulting in a highly efficient insulating material with low thermal conductivity. This allows for thinner insulation layers, providing savings in space and often reducing overall construction costs.

As for safety, the foam’s closed-cell nature means it doesn’t absorb water, protecting it from mould and bacterial growth. The foam’s unique composition also contributes to its superior fire resistance. It not only withstands high temperatures but also has minimal smoke emissions, further bolstering its safety credentials. Moreover, it doesn’t off-gas any toxic substances, a trait making it a safe choice for insulation in the building and construction industry.


Expanded Polystyrene, or EPS, is an insulation material recognisable by its white, bead-like appearance. It’s made from polystyrene which is expanded using steam and a blowing agent into rigid foam boards. This material excels in thermal insulation, soundproofing, and shock absorption, making it versatile across many applications, from insulating walls, roofs, and floors, to packaging materials.

Regarding safety, EPS is known for its inert nature. It doesn’t emit harmful gases or particles under normal conditions, making it safe to install in buildings. The material is also impervious to water, deterring mould and bacteria growth, which further safeguards indoor air quality. The production of EPS has also been improved over the years to eliminate the use of CFCs (Chlorofluorocarbons) and HCFCs (Hydrochlorofluorocarbons), known for their ozone-depleting effects.


2 thoughts on “Is Insulation Dangerous?

    1. Hi David, natural insulation is pretty safe in general. Rockwool/Mineral Wool is top of the range for most benefits. Sheep wool insulation also performs well in relation to fire, thermally, etc. But there is no real need to worry with phenolic foams and EPS as they’re rigorously tested and have to adhere to UK and EU standards in relation to fire. There’s also very little environmental impact due to the advanced manufacturing techniques.

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