Why We Don't Use Fiberglass or Rockwool — and Why It Matters for Your Indoor Air Quality
Here is a statistic that tends to surprise people: according to the EPA and the World Health Organisation, we now spend approximately 90% of our lives indoors. That figure has climbed steadily as working patterns, urban living and climate have shifted. It means that the air quality inside the buildings we occupy — our offices, homes, schools, restaurants and studios — has more influence on our health than the outdoor environment most of us instinctively worry about.
It is against that backdrop that we made a deliberate decision at QUNAS: none of our acoustic panels contain fiberglass or rockwool. This post explains why, what the documented health concerns are with those materials, and what we use instead.
The Standard Approach — and Its Problem
Fiberglass (glass wool) and rockwool (mineral wool) are the most widely used core materials in acoustic panels. They are inexpensive, widely available, and acoustically effective. For decades they have been the default choice across the industry, and the majority of acoustic panels on the market today still use one or the other.
The problem is not their acoustic performance. It is what they are made of. Both materials are classified as Man-Made Vitreous Fibres (MMVFs) — synthetic materials composed of fine, inhalable filaments. When those filaments become airborne and are breathed in, they are known to cause irritation to the respiratory tract, eyes and skin. The question worth asking — and one that most acoustic panel suppliers do not answer — is whether installed panels in occupied spaces pose a meaningful exposure risk.
What Health Authorities Actually Say
The health evidence on fibrous mineral materials is not speculative. The following is drawn from established health authority sources.
The Washington State Department of Health states directly:
"High levels of exposure to airborne fiberglass may aggravate existing asthma or bronchitis-like conditions." It further notes that the National Academy of Sciences has linked prolonged exposure to a potential increased risk of respiratory disease.
IARC — the International Agency for Research on Cancer, part of the WHO — originally classified glass wool as Group 2B (possibly carcinogenic to humans) in 1988. While this classification was later reconsidered based on evidence that glass fibres dissolve more readily in lung fluid than asbestos does, the respiratory irritation risk has never been in dispute. The distinction from asbestos is one of degree and mechanism, not of fundamental safety.
Rockwool carries the same category of concern. Both materials are documented irritants, and both carry acknowledged risks in environments where fibre release can occur.
When Does Fibre Release Happen?
There are two distinct points at which fibre release is a documented risk. Both are relevant to anyone specifying acoustic panels for an occupied building.
The first and most significant is installation. The following activities are known to release fibrous material into the air:
· Cutting or trimming panels to size
· Drilling or routing fixing points
· Handling unwrapped or bare panels
· Removing or replacing panels
The second risk is degradation over time. Acoustic panels installed in high-traffic environments — restaurants, school halls, open-plan offices — are subject to physical contact, humidity fluctuation and general wear. If the outer fabric facing of a panel becomes worn, punctured or detached, the fibrous core is exposed to the occupied space. Panels that were installed and forgotten about ten years ago, with no maintenance inspection, are the ones most likely to present a problem.
The physics of how acoustic absorption works also warrants honest acknowledgement. Absorption occurs because sound waves cause air to oscillate within the fibrous structure of the material — friction between the moving air and the solid fibres is what converts sound energy into heat. That same oscillating air movement is, over time, a plausible mechanism for the gradual dislodgement of loose fibres — particularly in panels that have begun to degrade. This is not a proven mechanism in the same way that installation-time exposure is, but it is consistent with how the materials behave and is a reasonable basis for caution.
What QUNAS Uses Instead — and Why It Matters
Every product in the QUNAS range uses one or more of three core materials: recycled PET fibre, natural sheep's wool, or sustainably sourced timber. None of these materials shed inhalable fibres in normal use. Here is what each one offers.
Recycled PET fibre
PET (polyethylene terephthalate) acoustic panels are made from post-consumer recycled plastic — the same polymer used in plastic bottles. The fibres in recycled PET panels are bonded together during manufacture into a stable, cohesive material. They do not shed particulate matter in normal use, do not off-gas VOCs, and contain no formaldehyde or other harmful binders. The material is safe for use in schools, healthcare environments and any occupied space where air quality is a priority. PET panels also achieve high NRC ratings — 0.80 or above at 50mm depth — making them acoustically competitive with fibrous mineral alternatives.
Natural sheep's wool
Sheep's wool offers acoustic performance alongside a set of active environmental benefits that no synthetic material can match. It naturally absorbs and permanently binds volatile organic compounds (VOCs) — airborne chemicals released by paints, adhesives and new furniture that are a known contributor to poor indoor air quality. It also regulates humidity by absorbing and releasing moisture vapour in response to changing conditions, helping to maintain a more stable and comfortable indoor environment. And it does not shed respirable fibres in the way that glass wool does — wool fibres are significantly larger in diameter and are not classified as inhalable at normal lengths.
Sustainably sourced timber
Timber is a natural, renewable material that requires no fibrous binders and poses no inhalation risk in finished, installed form. In our ARTAcoustic panels, the timber face works alongside a recycled PET core — combining the acoustic performance of PET absorption with the diffusion properties of a structured timber surface.
Who This Matters Most For
The indoor air quality implications of acoustic panel specification are relevant to any occupied building. They are particularly important in the following contexts.
The following types of project benefit most from material-conscious acoustic specification:
· Schools and educational facilities — children are more vulnerable to respiratory irritants, and classrooms are high-contact environments where panel wear and damage is likely over time
· Healthcare environments — hospitals, clinics and care homes require materials that pose no risk to patients with existing respiratory conditions
· WELL Building Standard and BREEAM projects — both frameworks include indoor air quality credits that are directly supported by the use of non-fibrous, low-emission acoustic materials
· Offices and open-plan workspaces — where workers spend the majority of their working day and where long-term, low-level exposure is the relevant risk profile
· Restaurants and hospitality venues — high humidity, physical contact and regular cleaning accelerate panel degradation, making material choice more consequential
A Different Standard
The acoustic industry has defaulted to fiberglass and rockwool for decades because they are cheap and easy to source. That is a reasonable commercial logic. It is not, however, a sufficient reason to use them in buildings where people work, learn, eat and sleep.
At QUNAS, the decision to build every product from recycled PET, natural sheep's wool and timber was not a marketing exercise. It was the outcome of asking a straightforward question: if someone is going to mount these panels on the walls of a space they occupy for eight or more hours a day, what is the safest and most responsible material to use?
The answer to that question is not fiberglass or rockwool.
Derek McCreanor is an acoustic consultant and the founder of Enhance Acoustics. QUNAS is the acoustic treatment product range designed and manufactured by Enhance Acoustics in Co. Offaly, Ireland. For product enquiries or acoustic consultancy, contact us at info@enhanceacoustics.com or visit www.enhanceacoustics.com.
