Unraveling the Mystery of Material Emissions in Buildings
You may be breathing in more than just air indoors, and the building itself could be the source.
Have you ever walked into a newly built apartment or a recently renovated room and been met with that distinctive "new building" smell? While it might signal freshness to some, that scent is actually the scent of chemical off-gassing—a cocktail of volatile organic compounds (VOCs) released by building materials and furnishings. In our modern world, where we spend up to 90% of our time indoors 9 , the quality of the air within our walls is not just a matter of comfort, but a critical component of our health and well-being. This article pulls back the curtain on the hidden world of material emissions, exploring the science behind the smells and what they mean for the places we live, work, and call home.
Indoor Air Quality (IAQ) refers to the air quality within and around buildings, especially as it relates to the health and comfort of its occupants 1 . At the heart of many IAQ concerns are Volatile Organic Compounds (VOCs). These are chemicals that easily evaporate at room temperature, turning from solids or liquids into gases that we inhale 8 .
The consistency of these chemicals indoors is a particular concern; the EPA has found that levels of several organic pollutants average 2 to 5 times higher indoors than outdoors 8 .
To truly understand the impact of material emissions, scientists conduct meticulous experiments that move from the controlled environment of the lab to the complex reality of actual buildings.
A pivotal study conducted in South Korea offers a fascinating in-depth look at how researchers measure these emissions in real-world conditions 6 . The experiment was designed to capture the air quality in newly-built apartments before occupants moved in, providing a clear picture of emissions coming solely from the building materials and construction, without the influence of residents' activities.
Researchers surveyed 107 newly-built apartments at the pre-occupancy stage across two metropolitan cities and one rural area. This diverse selection helped determine if outdoor urban pollution influenced indoor air quality 6 .
They collected air samples from both the interior of the apartments and the immediate outdoor environment. This allowed them to distinguish between pollutants originating from the building materials and those coming from outside 6 .
The study focused on measuring the concentrations of specific VOCs like toluene, ethylbenzene, and xylene, as well as formaldehyde—a well-known and potent indoor air irritant 6 .
Using the measured indoor air concentrations and a mathematical model (an indoor mass balance model), the team calculated the emission rates of these compounds. Essentially, they determined how much of each chemical was being released per hour from the surfaces inside the apartments 6 .
The findings were telling. The research confirmed that the "new building smell" is more than just an odor; it's a quantifiable mix of chemical emissions. The key discovery was that indoor concentrations and emission rates were not similar to those found in past studies 6 . This highlights a critical point: building material formulations change over time, and emission characteristics evolve, necessitating ongoing research.
The study successfully identified the primary sources of the VOCs. The results pointed to wood panels, vinyl floor coverings, wall coverings, adhesives, and paints as the most significant contributors to the indoor chemical cocktail 6 . Furthermore, by comparing apartments in different locations, the researchers concluded that outdoor VOC concentrations had a limited influence on the indoor levels, reinforcing that the building materials themselves were the dominant source 6 .
| Compound Type | Examples |
|---|---|
| Aromatics | Toluene, Ethylbenzene, Xylene |
| Alkanes | Undecane, Dodecane |
| Formaldehyde | Formaldehyde |
| Halogenated | Chlorobenzene |
| Ranking | Source Material |
|---|---|
| 1 | Wood panels & Vinyl floor coverings |
| 2 | Flooring materials |
| 3 | Wall coverings |
| 4 | Adhesives and Paints |
| Tool / Reagent | Primary Function |
|---|---|
| SUMMA Canister | A specially passivated, stainless steel container for collecting and storing whole air samples for later laboratory analysis. |
| GC-MS/FID | The workhorse instrument for separating, identifying, and quantifying individual VOC compounds in a complex air sample. |
| Field and Laboratory Emission Cell (FLEC) | A small, portable device that can be placed directly on a material surface to measure the emission rate from that specific source in real-time. |
| Indoor Mass Balance Model | A mathematical model that uses indoor concentration data, room dimensions, and ventilation rates to calculate emission rates. |
While VOCs are a primary concern for immediate indoor air quality, the environmental impact of building materials extends far beyond the walls of a single home. This is embodied carbon—the millions of tons of carbon emissions released during the entire lifecycle of building materials, including extraction, manufacturing, transport, construction, and disposal 5 .
of global greenhouse gas emissions from building embodied carbon 5
of total lifecycle carbon in energy-efficient buildings
As we construct more energy-efficient buildings with lower operational emissions (from heating and cooling), the relative share of embodied carbon in the building's total lifecycle impact grows. For a new, energy-efficient building, embodied carbon can represent more than 50% of its total life-cycle carbon footprint . This makes tackling embodied carbon an urgent climate action priority.
Energy-Efficient Building Carbon Footprint
The challenges posed by material emissions are significant, but they are not insurmountable. A multi-pronged approach can significantly improve the air we breathe indoors.
One of the simplest and most effective strategies is to increase ventilation, especially when using products that emit VOCs. This means opening windows or using exhaust fans to dilute indoor pollutants with fresh outdoor air 8 .
Be selective about the materials you bring indoors. Choose low-VOC or zero-VOC paints, adhesives, and finishes. When possible, select solid wood instead of products made from composite woods that can contain formaldehyde 9 .
Do not store open containers of unused paints, solvents, or chemicals inside your home or garage. For products you use only occasionally, buy only as much as you need right away to minimize stored chemicals 8 .
The market is increasingly offering sustainable alternatives. This includes using low-carbon concrete, recycled steel, and plant-based materials like wood, hemp, and bamboo that actually sequester carbon during their growth 5 .
Architects and builders can reduce a building's overall carbon and chemical footprint through efficient design—using less material without sacrificing strength, designing for durability and deconstruction, and opting for modular construction to minimize waste 5 .
The science is clear: the materials that form our built environment are active participants in determining the quality of our indoor air and the health of our planet. From the VOCs that create the "new building smell" to the embodied carbon hidden in concrete and steel, our choices matter. By understanding the sources of these emissions—from wood panels and vinyl flooring to paints and adhesives—we can make more informed decisions, advocate for healthier buildings, and support policies that prioritize clean air. The journey toward healthier indoor spaces is not just about eliminating harmful chemicals; it is about fundamentally rethinking how we design, build, and occupy our homes to ensure they are safe, sustainable, and truly supportive of human health.
The next time you catch a whiff of that "new" smell, you'll know the complex science and environmental impact behind it—and the steps you can take to breathe easier.