Concrete and Indoor Air Quality: Why Zero VOCs Matter

When people think about healthy buildings, they often focus on ventilation, natural light, and insulation. However, the materials used inside a building can also have a significant impact on indoor air quality.

One of concrete's lesser-known advantages is that it contains virtually no volatile organic compounds (VOCs) and does not off-gas harmful chemicals during its service life. This makes it an excellent choice for creating healthier indoor environments.

What Are VOCs?

Volatile Organic Compounds (VOCs) are carbon-based chemicals that evaporate into the air at room temperature. They are commonly found in products such as paints, adhesives, sealants, vinyl flooring, carpets, composite wood products, and some coatings.

High concentrations of VOCs can contribute to:

• Headaches and fatigue

• Eye, nose, and throat irritation

• Respiratory issues

• Poor indoor air quality

• Long-term health concerns associated with certain chemicals

• Many people are familiar with the "new building smell". In many cases, that smell comes from VOCs being released from building materials and finishes.

‍Why Concrete Is Different

Concrete is primarily made from cement, water, and aggregates such as sand and stone. Unlike many manufactured interior finishes, cured concrete itself produces negligible VOC emissions.

In fact, most VOC concerns associated with concrete projects come not from the concrete itself, but from:

• Sealers

• Coatings

• Adhesives

• Surface treatments

• Certain additives used during construction

When low-VOC or VOC-free finishes are selected, concrete can contribute to exceptionally low-emission indoor environments.

How Does Concrete Compare to Other Materials?

From an indoor air quality perspective, concrete performs very well compared with many common building materials.

• Concrete: Very low to negligible

• Painted plasterboard: Depends on paint system

• Vinyl flooring: Can emit VOCs, particularly when new

• Carpet: Often emits VOCs from fibres, backing and adhesives

• Particleboard/MDF: May emit formaldehyde and other VOCs

• Solvent-based coatings: Higher VOC emissions

• Timber finishes and stains: Can emit VOCs depending on product

This doesn't mean other materials are unhealthy. Many manufacturers now offer low-VOC alternatives. However, concrete starts with a natural advantage because the material itself is inherently low-emitting.

Does the Concrete Need to Be Exposed?

This is one of the most common questions.

The short answer is: not necessarily.

If a concrete wall is exposed internally, occupants can benefit directly from the material's low VOC profile. Because the exposed surface is not coated with plasterboard, vinyl wall coverings, paints, or other finishes, there are fewer potential sources of indoor emissions.

However, even when concrete walls are lined, concrete can still contribute positively to indoor air quality because it is not adding VOCs to the building. The benefit becomes less noticeable because the indoor air is then influenced more by the materials applied over the top, such as:

• Plasterboard

• Paint systems

• Adhesives

• Wall coverings

• Insulation products

In other words, a lined concrete wall remains a low-emission structural system, but the overall indoor air quality outcome depends largely on the finishes selected.

The Bigger Picture: Creating Healthier Buildings

Healthy indoor environments are rarely the result of a single building material. They come from thoughtful choices across the entire project.

Concrete can play an important role because it offers:

• Negligible VOC emissions

• Long service life

• Durability without frequent replacement

• Compatibility with low-emission finishes

• Thermal mass that can improve comfort and energy efficiency

When combined with low-VOC paints, adhesives, flooring products, and good ventilation, concrete can help create spaces that support occupant wellbeing for decades.

Building for Health and Performance

At Homestead, we believe great buildings should be designed for more than strength and appearance. They should also support the health and comfort of the people who use them every day.

Concrete's naturally low VOC profile is one more reason it remains one of the most trusted building materials available. Whether left exposed as an architectural feature or incorporated into a wider construction system, concrete provides a solid foundation for healthier indoor environments.