What’s in it · straight off the safety data sheet
What is cellulose insulation made of? Paper, boric acid and borax.
Shredded newsprint paper and two borate minerals. On the safety data sheet it’s 80% shredded newsprint, 12% boric acid, 8% borax by weight. That’s the whole list. No ammonium sulphate, no formaldehyde, no glass fibre.
I’m Peter Johnson. We make this stuff ourselves at Tiaro, so I’m not reading you a brochure from a supplier. Here’s the actual document, what each ingredient is doing in there, and the one study people sometimes wave at me.
80% paper · 12% boric acid · 8% borax
tap the sheet to read it
Real reviews, real jobs
What our customers say
Genuine Google & hipages reviews from Comfort Zone customers across SE Queensland.
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Angela M.
SE Queensland
“The fact that I can't even tell it's 6 degrees outside when I wake up in the morning speaks for itself. Have wasted so much money attempting to heat and cool an uninsulated home. Worth every $.”
- Phipages
P Peter
Alstonvale, 2024
“Connected with Comfort Zone Insulation and would recommend them”
- J
Jessa B.
Brisbane
“It dropped about 4 degrees straight away, and we added another 3 with the second job. I appreciate Peter's honesty, and the team showed pictures before and after.”
- Nhipages
Nola M
Birtinya, 2024
“They were courteous and competent.”
- I
Iain V-B.
Brisbane
“Quick and polite service. Great follow-up advice and photos sent for our records. Above and beyond what we expected. Would highly recommend.”
- Jhipages
Jennifer's E
Upper Caboolture, 2024
“Excellent customer service. Highly recommended. Has a profound knowledge of insulation products and has the best interest of his customer.”
- G
Gerry S
Fitzgibbon, 2023
“I used Comfort Zone and they have a done an excellent job.”
- Jhipages
Jennifer
Upper Caboolture, 2024
“Excellent customer service. Highly recommend. Has a profound knowledge of insulation products and has the customer best interest.”
- J
Jung K
Riverhills, 2023
“An experienced family operation. Highly recommend. Thank you for the great job!”
- Dhipages
Diane A
Ormeau, 2024
“Peter and crew did a great job I would definitely recommend them”
- D
David H
Sunshine Coast, 2021
“Completed the job as quoted and to a high standard. Great personal service. Would highly recommend Comfort Zone for ceiling installation work.”
- Thipages
Timea
Highland Park, 2023
“I was extremely satisfied with the service they provided. They gave a very thourough explanation of the materials used, the way the work will be carried out and the price I had to pay was the exact amount quoted, no hidden costs included. They arrived on time, well prepared and workwas carried out exactly how they said it would be, they were super efficient, well prepared and were kind enough to even clean up after themselves. The services they provided was second to none! I don't hesitate to recommend them for any insulation job!”
- B
Benjamin H
Carseldine, 2019
“Very good explanation about their works. Advice of existing problems with the roof. Clean work. Very professional.”
- Mhipages
Mark
Pottsville, 2017
“Michelle, we are done - Peter from comfort zone insulation was very helpful. very honest with his recommendations - in fact he told me that the product my daughter had if installed correctly was superb. Thanks Peter you are a champion and i would recommend you to any person that was wanting professional advice and old school service.”
- I
Ian G
Burnside, 2019
“Good information, communication and professionalism.”
- Jhipages
Jessica
Pottsville, 2016
“This business offers a fantastic product that other businesses did not. Pump in ceiling insulation. Knowledge of the industry second to none.”
- D
Danny D
Boondall, 2018
“He explained everything he was going to do and the different types of insulation they used. He talked through the different options but made a recommendation for the one most people use, which is the one I chose. He was very understanding towards what I needed and not about himself.”
- Jhipages
Jack
Pottsville, 2023
“Excellent communication and informative. Professional.”
- G
Graham R
Riverhills, 2018
“Comfort Zone. Turned up ahead of time, completed in about 2 hours, cleaned up. All good. Very motivated installation team.”
- Thipages
Tony P
Redland Bay, 2023
“Very knowledgeable about insulation”
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Alex B
West Ipswich, 2018
“Fast, friendly, efficient.”
- Shipages
Steve
Redland Bay, 2017
“Excellent job and reasonable price.”
- L
Luke D
Mcdowall, 2017
“Peter did a good job. It was a quick and clean service. I'm happy to recommend!”
- Bhipages
Bruce H
Kuluin, 2023
“Prompt and efficient quoting.”
- B
Brendon
Brays Creek, 2016
“Peter supplied and installed roof insulation for me. He was very informative and provided good advice.”
- Ghipages
Gerry S
Fitzgibbon, 2023
“I used Comfort Zone and they have a done an excellent job.”
- T
Trevor G
Brookside Centre, 2016
“Excellent tradesmen from Comfort Zone Insulation. They were punctual and cleaned up after. Highly recommended.”
- Thipages
Tamara
Underwood, 2023
“Peter is honest, hard-working and came on time. Knew excally what he was talking about and answered my questions. Would 100% recommend”
- J
John G
Beaudesert, 2019
“Peter is an honest person who provided me with the information I wanted then performed a good job with great results for the benefit of myself and my family.”
- Shipages
Sterling G
Ashgrove, 2023
“Comfort Zone were very knowledge with great communication and follow up”
- Ghipages
Graham R
Riverhills, 2018
“Comfort Zone. Turned up ahead of time completed in +- 2 hours cleaned. All good. Very motivated installation team”
- Jhipages
Jung K
Riverhills, 2023
“An experienced family operation. Highly recommend. Thank you for the great job!”
- Khipages
Kathy A
North Lakes, 2023
“We connected with Peter through HiPages and he was prompt, professional and even came back after the job was complete to assist with a question we had. We would highly recommend Peter for further insulation works.”
- Dhipages
David H
Sunshine Coast, 2021
“Completed the job as quoted and to a high standard. Great personal service. Would highly recommend Comfort Zone for ceiling installationn work.”
- Shipages
Sue H
Sunshine Coast, 2021
“Incredible customer service”
- Ehipages
Eileen C
Cedar Vale, 2021
“Quality work, good customer service, prompt”
- Chipages
Craig M
Woody Point, 2021
“Called within 5 minutes of request. Very knowledgeable and explained job in great detail, provide great advice in prior preparation for works required. Very friendly and helpful.”
- Jhipages
Jenny C
Plainland, 2021
“Although I did not hire Peter I was impressed with the initial contact and the knowledge he was willing to impart. I was treated with respect which I appreciated. I would have hired but I received a lower quote.”
- Qhipages
Quinton
Coomera, 2020
“Professional installation without any short cuts. True to their word with high integrity. Response from Comfort Zone Insulation”
- Ghipages
Gary P
West Kempsey, 2020
“Came & Gave a free quote”
The whole ingredient list
Three ingredients. That's it.
Most building products need a paragraph to explain what's in them. This one needs a line.
80%
Shredded newsprint paper
Recycled Australian waste paper, milled down to a fibre. This is the insulation itself. Paper fibre traps air, and trapped air is what stops heat moving. Nothing exotic about it.
12%
Boric acid
A mineral salt. This is the main fire retardant. It's the reason a flame chars the fibre and stops rather than running across it.
8%
Borax decahydrate
The other borate. Between them they make the roof a place insects won't live in, and they resist mould and fungal growth.
The two borates together come to about 20% of the weight of the finished product, which works out to roughly 3% elemental boron. If you ever see cellulose analysed with traces of clay in it, that’s not an additive. Glossy printed paper carries clay as a filler, so it arrives with the recycled stock.
Not a brochure
The document those numbers come from.
A Material Safety Data Sheet is the regulatory document that has to tell the truth about what's in a product. It's written for the people handling it, not for selling it.
Page one is the identification and the ingredients. A few lines on it are worth pulling out, because they answer questions people ask me all the time.
- Spread of Flame Index: 0Zero is the best result there is on that scale. It's the measured reason a blowtorch chars a handful of this and goes no further.
- UN Number, Hazchem Code, Dangerous Goods Class: all "Not applicable"It isn't a dangerous good. No UN number, no placard, no dangerous-goods paperwork — it goes on the truck like any other bag of building material.
- Percent volatiles: no noxious volatilesThere's nothing in it to off-gas. It doesn't cure and it doesn't keep reacting.
- Stability: stable. pH: slightly alkaline.It stays what it is. The borates don't evaporate out of it or wash away in a dry ceiling.
What you’re looking at, and what you’re not
That’s page one of the sheet. There are further pages covering health information and safe handling, and the short version of those is: wear a mask and goggles while you’re installing it, which we do. Page two also mentions a 1992 rat study, and rather than leave that hanging I’ve set out below exactly what that study was.
The product is also made to AS/NZS 4859.1, the Australian Standard for thermal insulation materials. The references page lists the paperwork behind that.
Why a mineral salt is in your ceiling
What the borates are actually for.
Two jobs: fire, and everything that would otherwise want to live up there.
Paper burns. Borate-treated paper doesn’t carry a flame. Hold a torch to a handful of this and it chars and glows a crater where the flame touches, then stops when you take the flame away. That’s the Spread of Flame Index of 0 on the sheet. It’s a demonstration you can watch rather than a marketing line.
The second job is pests. Borax is a natural insect killer, so the ants, spiders, silverfish and cockroaches that infest a roof won’t set up in it. It doesn’t kill rodents and I won’t tell you it does. What it does is take away their food, and a loose fibre blanket is no good to nest in, so between the two of them rats and mice go elsewhere. Being borate-treated it resists mould and fungal growth too, which is why a 40-year-old cellulose roof is a far cleaner place than a 40-year-old batt roof.
Where this sits in the rules, and the documents to check it
People sometimes ask whether a borate treatment makes this a scheduled poison. Boric acid does appear in Schedule 5 of the Poisons Standard, with a general exemption for preparations at 6% or less. Ours is stronger than that, so that limb doesn’t cover us.
What does cover us is the same instrument’s Appendix A, which grants a general exemption to “PAPER except: (a) when prepared for pesticidal use; or (b) when containing a poison included in Schedule 8 or 9”. Boric acid is Schedule 5, so limb (b) doesn’t apply. The same appendix exempts “TIMBER or WALLBOARD”, which is why the borate-treated pine holding your roof up carries no schedule number either.
Ours is a paper product made to insulate. The borate is in it as a fire retardant — that is what our own safety data sheet calls it, a fireproofing agent — and insects not living in treated paper is a consequence of that, not the reason it’s there. I’m setting the documents out here so you can read them yourself rather than take my word for it.
People ask about the boron itself. It isn’t a foreign substance to a human body — it’s a mineral your body uses. And you can buy it in a multivitamin at any chemist. Borax has been in laundry cupboards for over a century. I’m not telling you to eat insulation. I’m telling you the treatment in it is a mineral salt in the same league of nasty as the salt on your table.
Comfort Zone insulation.team
Family-owned insulation manufacturer, making comfy homes since 1986
A batch flame test at the factory. The crater is where the flame was held. It went out on its own the moment the flame came away.
The question I get from every second customer
“But what about the ink on the newspaper?”
Fair question, and somebody thought to test it. The safety data sheet records that the material was tested by an independent laboratory for PAH carcinogenic content from the oils used to make the ink on the newsprint. The result printed on the sheet: no PAHs were detected.
The ink people picture is the old solvent-based kind. Newsprint ink these days is largely soy and water based. It’s bound into the paper fibre rather than sitting loose on it. If you want the longer version of the off-gassing question, it’s covered on does cellulose off-gas.
The one thing on page two worth explaining
About that 1992 rat study.
It gets quoted at me now and then, so here's what it actually was, in full, including the bit that doesn't help me.
In 1992 some researchers put rats in a chamber and had them breathe cellulose insulation dust for six hours a day over four weeks. The rats’ lungs got inflamed, and the more dust they breathed the worse it got. That’s the study, and I’m not going to tell you it didn’t happen. It’s referenced on page two of our own safety data sheet.
The part that matters is what they had to do to the insulation first.
| What the rats were given in 1992 | 38–47% |
| Real cellulose insulation dust, measured by the US government at ten working job sites | under 0.1% |
The researchers ground the product down until nearly half of it was fine enough to reach the deep lung, because ordinary cellulose insulation doesn’t produce enough of that fine fraction to run the experiment at all. That’s hundreds of times more breathable dust than comes off a real job. It isn’t an exposure a worker could get, and it certainly isn’t one a person living in the house could get.
You don’t have to take my word for that. When the US National Toxicology Program reviewed the study in 2006, they wrote it up themselves:
“the CI exposures in this study were not representative of workplace exposures to CI.”
US National Toxicology Program, Report TOX-74 (2006), page 16, on Hadley, Kotin and Bernstein (1992). Read the report (PDF)
And on the word people reach for
The study found inflammation and tissue changes in the rats’ lungs. It did not find cancer, and it wasn’t built to look for it. Four weeks is a short-term toxicity study; a cancer study runs for two years. Nobody has ever run one on cellulose insulation, and when the US government looked at whether one was needed, they decided the material didn’t warrant it.
The most recent work is the one I’d point you at. In 2019 researchers ran a properly controlled inhalation study on actual borate-treated cellulose insulation, unmodified, at concentrations well above anything on a job site. They found no adverse effects at the highest dose they tested.
What I’m not going to claim
That breathing any dust is fine. It isn’t. The US government’s position is that cellulose insulation should be treated as a nuisance dust, with masks worn while it goes in. Our own safety data sheet says the same thing. That’s what we do on every job. Any dust in a hot roof space is worth a mask, whatever it’s made of.
The difference is what happens after we leave. The insulation settles into your ceiling and stays put. There’s no fine glass fibre in it waiting to work its way back down through your downlights.
Made and installed by the same people
When you ask what’s in the bag, you’re asking the people who filled it.
Most insulation sold in Australia is imported, or made by a company that never sees the inside of a roof. Ours is milled at our own factory in Tiaro from recycled Australian waste paper, bagged there, and then put in your ceiling by us. My sons Noah and Eli work in the business. That’s why I can answer a question about the ingredients without ringing a supplier.
Straight answers
What-it's-made-of questions I get asked.
What is cellulose insulation made of?+
Shredded newsprint paper and two borate minerals. On the safety data sheet for the Cellulose Fibre Thermal Insulation we make, it's 80% shredded newsprint paper, 12% boric acid and 8% borax by weight. That's the whole ingredient list. The paper is the insulation, because it traps air. The borates are what make it fire-retardant and stop insects living in it. There's no ammonium sulphate in it, no formaldehyde and no glass fibre.
Is borax dangerous to have in my ceiling?+
Borax is a naturally occurring mineral salt. It has been sold in supermarkets for over a century as a laundry booster and cleaning product. It's about as toxic to a person as table salt, which is to say don't eat it. It's bound into the paper fibre sitting above your plasterboard, not floating around your house. Boron is also a mineral your body actually uses; you can buy it in multivitamins on a chemist's shelf. What the borates are there for is fire and insects, and they don't wear out or evaporate the way an added chemical might.
Is the ink on the recycled newspaper a problem?+
It was tested, and that test is printed on the safety data sheet. An independent laboratory checked the material for PAH carcinogenic content from the oils used to make the ink on the newsprint, and the sheet records that no PAHs were detected. Modern newsprint ink is largely soy and water based rather than the solvent inks people picture. Trace clays sometimes turn up in cellulose analysis too. That's simply because glossy printed paper carries clay as a filler; it isn't something anybody adds.
Does cellulose insulation off-gas?+
No. The safety data sheet lists no noxious volatiles, and the product is stable. There's nothing in it that cures, reacts or keeps releasing anything once it's in your roof, because it isn't made by mixing chemicals on site the way spray foam is. It's paper and mineral salts. It's the same the day it goes in as it is in thirty years.
Who actually makes it?+
We do, at our own factory in Tiaro, Queensland, from recycled Australian waste paper. That's unusual in this trade; most insulation sold in Australia is either imported or made by a company that never sees the inside of your roof. It means when you ask what's in the bag, you're asking the people who put it in the bag. My sons Noah and Eli work in the business. It's the same family that makes it and installs it.
Do you wear a mask installing it?+
Yes, every time, and so should anyone else. The safety data sheet recommends respiratory protection during installation. The US government's own toxicology review says cellulose insulation should continue to be regarded as a nuisance dust with masks worn while it's being installed. Any dust in a confined roof space is worth keeping out of your lungs, whatever it's made of. That's a handling precaution during the job, not something that carries on once the insulation is sitting in your ceiling.
Want it in your roof?
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Fixed price by email, usually within 48 hours. No deposit, and no inspection to book first. Made at Tiaro, installed by us, and backed by a transferable Life-of-House guarantee.
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