Is Cellulose Blown-In Insulation Fire Retardant?

When it comes to choosing insulation for your home, fire safety is one of the most important factors to consider. Many homeowners ask, “Is cellulose blown-in insulation fire retardant?” It’s a valid question—after all, cellulose is made from recycled paper products, which might sound like a fire hazard at first. However, the truth is that cellulose insulation is one of the safest and most fire-resistant insulation options on the market today.

At Koala Insulation of Superstition Springs, we help homeowners throughout the East Valley of Arizona make informed decisions about insulation that protect their families and enhance home performance. In this blog, we’ll explain what cellulose insulation is, how it’s treated for fire resistance, and why it can be a smart, safe choice for your attic or walls.

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What Is Cellulose Blown-In Insulation?

Cellulose blown-in insulation is a loose-fill material primarily made from recycled newspaper, cardboard, and other paper-based products. These materials are shredded into small particles and treated with fire-retardant chemicals to create a dense, fluffy insulation that’s blown into wall cavities, attics, and other spaces using special equipment.

Benefits of cellulose insulation include:

• High R-value (thermal resistance)
• Eco-friendly composition
• Excellent air sealing capabilities
• Superior soundproofing
• Cost-effective compared to spray foam

But perhaps one of its most surprising features is its strong fire retardant qualities.

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Is Cellulose Insulation Really Fire Retardant?

Yes. Despite being made from paper, cellulose blown-in insulation is treated with fire-retardant chemicals that make it highly resistant to ignition and flame spread. In fact, cellulose insulation often outperforms fiberglass and other materials in fire safety tests.

The key lies in the fire-retardant additives used during manufacturing. These additives include:

• Boric Acid
• Ammonium Sulfate
• Aluminum Sulfate

These non-toxic, mineral-based chemicals are added to cellulose insulation to:

• Reduce combustibility
• Slow the spread of flames
• Minimize smoke production
• Self-extinguish if the fire source is removed

The result is a product that meets or exceeds all local and national fire safety standards, including those set by the ASTM (American Society for Testing and Materials) and Underwriters Laboratories (UL).

At Koala Insulation of Superstition Springs, we only install cellulose insulation that meets strict fire retardant standards to ensure your family’s safety and peace of mind.

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How Fire Retardant Is It Compared to Other Insulation?

Let’s compare cellulose insulation to other common insulation types in terms of fire performance:

Insulation Type	Fire Resistance	Treatment Required	Notes
Cellulose	High	Yes (chemically treated)	Slows fire spread and suppresses flames
Fiberglass	Moderate to High	No (naturally non-combustible)	Can melt at high temps but won’t ignite easily
Spray Foam	Varies by type	Yes (fire retardants added)	Can ignite or off-gas unless covered by thermal barrier
Mineral Wool	Very High	No (naturally fire-resistant)	Ideal for fire-rated assemblies

While fiberglass and mineral wool are inherently non-combustible, cellulose is unique in that it offers both superior thermal efficiency and fire protection after treatment. Its dense application also helps slow the flow of oxygen, which further hinders combustion.

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What Happens to Cellulose in a Fire?

If cellulose insulation is exposed to fire, its chemical treatment causes it to char rather than ignite. The charred layer helps insulate the material beneath and slows the progression of the fire. This gives occupants more time to evacuate and allows firefighters a better chance to contain the blaze before it spreads.

Unlike untreated materials, cellulose doesn’t drip, melt, or emit toxic fumes when heated. This makes it a safer choice for attics, walls, and ceilings—particularly in older homes undergoing energy retrofits.

At Koala Insulation of Superstition Springs, we often recommend cellulose for fire-prone areas or homes that need extra protection without the high cost of more specialized systems.

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Additional Safety Benefits of Cellulose Insulation

Beyond fire resistance, cellulose blown-in insulation offers other benefits that contribute to a safer home:

• Tighter Air Sealing: Reduces airflow that could fuel a fire and contributes to HVAC efficiency.
• Reduced Drafts and Cold Spots: Keeps conditioned air where it belongs while maintaining consistent indoor temperatures.
• Sound Dampening: Minimizes noise transfer between rooms and from outside, creating a more peaceful living space.
• Eco-Friendly Composition: Made from up to 85% recycled content, cellulose is one of the greenest insulation materials available.

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Where Should You Install Cellulose Insulation?

Cellulose insulation is extremely versatile and can be used in several parts of the home:

• Attics: Ideal for blown-in coverage that blankets the space and fills gaps.
• Wall Cavities: Can be dense-packed into wall studs for air sealing and soundproofing.
• Crawl Spaces and Basements: Offers thermal protection and fire resistance in vulnerable areas.

In Arizona’s hot climate, cellulose is particularly effective at keeping homes cooler in the summer, reducing strain on your HVAC system, and lowering energy costs. Koala Insulation of Superstition Springs tailors each installation to your home’s structure and your performance goals.

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Trust Koala Insulation of Superstition Springs

Our team is highly trained in the safe and effective installation of cellulose blown-in insulation. We only use products that meet rigorous fire safety standards, and we take pride in offering personalized service and long-term protection for your home.

When you choose Koala Insulation of Superstition Springs, you’re not just getting insulation—you’re getting peace of mind. We serve homeowners in Mesa, Apache Junction, Gold Canyon, and throughout the East Valley with expert insulation solutions backed by industry knowledge and customer-first care.

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Call for Your Free Estimate Today

If you’re considering an insulation upgrade and want fire-resistant, eco-friendly, and energy-saving performance, cellulose blown-in insulation is a smart choice. Our team can assess your needs and recommend the best solution for your home and budget. Call Koala Insulation of Superstition Springs today at (480) 681-5151.