Cellulose vs. Asbestos Insulation: How to tell apart?

Insulation is a critical component of any energy-saving strategy. Because without proper insulation, no amount of heating or cooling will work to meet desired thermal expectations.

However, not all insulation is created equal. There are many different types of insulation on the market, each with its own set of properties.

When selecting an insulation material, it is critical to consider a number of factors such as energy performance, cost, public health, durability, and environmental impact.

Because only then can you be certain of getting the best insulation for your project.

In this post, we will talk about two insulations that are often confused: cellulose and asbestos.

Although both of these materials have a unique look and feel they can still be confusing even for construction professionals.

So, let’s see what makes them different from one another.

What is Cellulose Insulation?

Cellulose insulation is plant-based insulation made of recycled materials like newsprint, cotton, straw sawdust, and hemp. However, the most common source of cellulose insulation is still newsprint.

It is typically grey-colored due to the presence of ink in recycled newsprints. However, depending on the utilized raw material and the manufacturing process, the color of cellulose insulation can vary from light yellow to dark brown.

cellulose insulation made from recycled paper

Cellulose insulation is a fluffy material that looks like cotton candy without giving you the same appetizing impression.

Since the raw materials that make cellulose insulation are highly combustible, the insulation is treated with a fire retardant. This treatment also makes the cellulose insulation resistant to pests and moisture.

Cellulose insulation typically doesn’t irritate the skin when contacted. Although cellulose insulation is made of plant-based materials, it will still have an additional chemical content that comes from the material content like ink.

Newspaper inks contain a variety of chemical extracts and organic solvents, including di-isobutyl phthalate, ethanol, dimethyl sulfoxide or DMSO, di-n-butyl phthalate, and propanol.

Ink pigments are quite small in size and are high in heavy metals such as lead, cadmium, or chromium, which are toxic when exposed to the skin or ingested.

Also, manufacturers add a fire retardant during the manufacturing process that prevents cellulose insulation from catching on fire. The most common flame retardants used in cellulose insulation are boric acid and ammonium sulfate.

Therefore, don’t treat cellulose insulation like a fully natural product. It still has chemical content that should not be ingested or come in contact with your skin especially if you have allergies.

Handling of cellulose insulation should be done with gloves and a dust mask to avoid any respiratory problems or skin irritation.

That said, cellulose insulation is still more eco-friendly than most other types of insulation materials. Because it utilizes materials that would otherwise go in landfills.

By recovering them, cellulose insulation is able to reduce the amount of solid waste we produce.

Also, manufacturing cellulose insulation doesn’t require as much energy as other insulation materials.

Because it doesn’t have energy-dependent raw material extraction from the earth as well as intensive processing. That means cellulose insulation has typically a lower embodied energy than other insulation materials.

For those who don’t remember what embodied energy is, it’s the total amount of energy that was used to produce a product.

It encompasses the energy required for raw material extraction, manufacturing, transportation, and delivery. The lower it is, the more environmentally friendly the product is.

Most cities or regions around the world will easily reach the raw materials that make cellulose insulation.

So, it is easier to source them locally without depending on the lengthy transportation & import/export issues. This further reduces the embodied energy of the product.

A short history of cellulose installation use

The first known use of cellulose insulation was in 1772. It was used to insulate Monticello in the United States. From the 1920s onwards, cellulose was widely employed as an insulating material throughout the country.

Initially, cellulose insulation was made from ground-up newsprint. But, with the advent of new technologies and increased demand for cellulose insulation, other materials like cotton, cardboard, straw, sawdust, hemp, and corncob fiber were added to the list of raw materials.

However, modern cellulose insulation began in the 1950s and became widely used in the US in the 1970s.

After the 1973–1974 oil crisis, demand for insulation increased. Rising heating costs throughout the US prompted people to seek energy-saving strategies. Insulation attracted national attention as a cost-effective approach to enhance home energy efficiency.

In response to a particularly harsh winter in 1977, the United States government passed the National Energy Conservation Policy Act. This policy gave rise to a federal program for energy audits and tax credits on insulation products.

Due to retailer, contractor, and consumer complaints regarding price, safety, and quality control issues, the federal government began enforcing insulation requirements in 1978.

Despite the lack of accurate national statistics, there were widespread concerns that the boom in cellulose manufacturing was resulting in incorrectly or inadequately treated insulation against the threat of fire.

As a result, the Federal Consumer Product Safety Commission passed 16 CFR Part 1209, which establishes safety criteria for four cellulose insulation product qualities only: settled density, corrosiveness, critical radiant flux, and smoldering combustion.

Another rule that was enacted was the “R-value Rule“, which established defined limits on the claims that manufacturing and marketing firms might make about their products.

Cellulose insulation is currently widely used in the United States, Europe, and Asia for both retrofit and new construction applications.

One of the reasons for its popularity is that cellulose insulation may be more fire-resistant than other types of insulation, such as fiberglass. Because cellulose is denser than fiberglass, it restricts the oxygen required for combustion.

Also, cellulose has the greatest recycled content of an insulating material and the lowest embodied energy of fiberglass and other mineral insulations produced in a furnace.

What is Asbestos Insulation?

Asbestos insulation is made of asbestos, a naturally occurring fibrous silicate mineral.

It has excellent insulating and fire-resistant properties. Therefore, it has been used for many years not only in homes but also in ships, aircraft, and industrial facilities.

Asbestos Insulation wraps pipe

Asbestos insulation can be almost in any color you can imagine. Because the term “asbestos” covers a wide range of minerals. These minerals are classified as asbestos by the Asbestos Hazard Emergency Response Act (AHERA).

The color of asbestos insulation is usually associated with the type of asbestos it contains. Here are the most common types of asbestos and their corresponding colors:

Chrysotile (white asbestos) is the most prevalent form of asbestos. It is still utilized in homes and businesses’ roofs, ceilings, walls, and flooring.

Manufacturers also used chrysotile asbestos in automobile brake linings, gaskets and boiler seals, and insulation for pipes, ducts, and appliances.

Amosite (brown asbestos) was mostly utilized in cement sheets and pipe insulation. It’s also present in ceiling tiles and thermal insulating products, among others.

Crocidolite (blue asbestos) was commonly used to insulate steam engines. It was also used in spray-on coatings, pipe insulation, and cement products.

Anthophyllite was utilized in small amounts for insulation and construction materials. It’s also found in chrysotile asbestos, vermiculite, and talc. It can be grayish, dull green, or white.

Tremolite and actinolite are not commonly used in industry, but they can be present as impurities in chrysotile asbestos, vermiculite, and talc.

These two chemically related minerals come in a variety of colors, including brown, white, green, gray, and transparent.

Types of AsbestosCorresponding Colors
Chrysotile (white asbestos)White
Amosite (brown asbestos)Brown
Crocidolite (blue asbestos)Blue
AnthophylliteGrayish, dull green, or white
Tremolite and actinoliteBrown, white, green, gray, and transparent

These six forms of asbestos were authorized for regulation by the AHERA in 1986, and they are now prohibited in over 50 countries worldwide.

It’s now known that there are other asbestos-like minerals that aren’t prohibited or regulated by the US Bureau of Mines and the National Institute for Occupational Safety and Health (NIOSH). So winchite, richterite, erionite, and taconite contain asbestiform fibers and have been linked to asbestos-related diseases.

If you live in an older home built before 1980, it’s highly probable that you have asbestos insulation. It was used in most homes’ walls and ceilings until the mid-1970s.

Asbestos is difficult to identify visually. Because asbestos ore comes in a variety of colors, including white, green, blue, and brown which are transformed into fluffy fibers.

The only way to know for sure if your home has asbestos insulation is to have it tested by a professional.

While asbestos fibers are not typically visible in asbestos-containing products, they may be seen once the product is disturbed.

Many household products that are made of plastic or cement can still contain tiny fragments of asbestos. When these materials are disturbed tiny asbestos fibers, resembling frayed fabric can be seen.

However, finding out these fibers does not necessarily mean that the material contains asbestos.

Again, asbestos can only be surely detected by laboratory testing. While homeowners can collect and test samples, it is much safer for you and your family to engage qualified asbestos professionals.

Don’t touch or disturb any insulation product if you aren’t 100% sure that it’s asbestos-free. Otherwise, the fibers can be released into the air and inhaled.

If you aren’t sure what type of insulation you have on certain parts of your home, assume that they are made of asbestos.

Because asbestos insulation was used in so many applications including attic insulation, vinyl floor tiles, popcorn ceilings, furnace insulation, piping insulation, and more.

Therefore, when it comes to asbestos, don’t take any chances. Leave the identification and removal to the professionals.

A short history of asbestos installation use

Although asbestos has been used since the Stone Age to strengthen pottery pots, large-scale mining began in the late 19th century when manufacturers and builders discovered its beneficial physical qualities.

Asbestos insulation, which is made of asbestos fibers, was widely used in the United States prior to the 1970s. It was used to insulate everything in a house, including the ceilings, walls, floor tiles, and even the water piping.

Given its superior electrical insulation and fire resistance, asbestos was widely employed as a building material throughout the twentieth century, until its harmful effects on human health were discovered in the 1970s. Many pre-1980 modern buildings may still contain asbestos.

The EPA banned spray-applied asbestos-containing fireproofing/insulation on buildings, structures, pipes, and conduits having more than 1% asbestos in 1973.

The EPA thus outlawed asbestos pipe and block insulation as facility components, as well as on boilers and hot water tanks, unless the material was pre-formed (molded) and friable, or applied wet and friable after drying.

The EPA broadened the prohibition in 1978 to all spray-applied surface materials not covered in 1973.

Many countries have banned the use of asbestos in construction and fireproofing. Despite this, asbestos-related diseases kill at least 100,000 individuals per year.

Partly because many older buildings still contain asbestos, and partly because the effects of exposure can take decades. Many developing countries still use asbestos as a building material.

Asbestos is classified by the US Government as a Category I human carcinogen. It is known to cause mesothelioma, a rare form of cancer that attacks the lining of the lungs, abdomen, and heart.

Asbestosis is a scarring of the lung tissue that makes breathing difficult and can cause fatal complications.

Don’t touch or breathe asbestos insulation or any type of insulation without proper training, equipment, and safety precautions.

Now that we have that out of the way, let’s take a look at some key differences between cellulose and asbestos insulation:

PropertiesCellulose InsulationAsbestos Insulation
Material CompositionRecycled newspaper, cardboard, wood chips, straw sawdust, hempNaturally occurring fibrous silicate mineral
Manufacturing ProcessGround-up raw materials are treated with a fire retardantMined from the earth and then processed by crushing and grinding
DensityLighter and fluffier compared to asbestos insulationHeavier and denser than cellulose insulation
Insulating PropertiesGood thermal insulation propertiesGood thermal and sound insulation properties
DurabilityCan settle and lose insulation properties over timeDurable and can last for decades
Moisture ResistanceResistant to moistureSusceptible to moisture damage
Health HazardsContains ink pigments and chemical extracts, wear gloves and dust mask when handlingContains asbestos fibers, can cause serious respiratory diseases
Environmental ImpactMore eco-friendly, utilizes recycled materials, lower embodied energyHazardous waste, harmful to the environment
History of UseFirst used in 1772, widely used in the 1970sWidely used prior to the 1970s, banned in many countries due to health hazards
Cellulose Insulation vs Asbestos Insulation – Properties Comparison.


Cellulose insulation is made of recycled newspaper, cardboard, and wood chips. It looks fluffy gray, yellow, or brown depending on the raw materials and treatment additives used in the manufacturing process.

Asbestos insulation similarly can be in almost any color depending on the mineral it is made of, but it is more commonly white.

Therefore, if you have an insulation product you are not sure what type of insulation you have, assume that it is asbestos.

The chances of encountering asbestos in a home built before 1980 are very high, and it can be present in many insulation products. Don’t take any chances. Leave the identification and removal to the professionals.

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