Indoor Air Quality and Interior Material Choices

Indoor air quality and interior material choices are inseparable, yet the connection is frequently overlooked during the specification process. Every flooring product, wallcovering, adhesive, and fabric in a building releases chemical compounds into the air. In Singapore, where buildings are sealed and air-conditioned for most of the year, these emissions accumulate in the indoor environment rather than dissipating through natural ventilation.

Understanding how interior materials affect air quality, and how to specify products that protect occupant health, is essential knowledge for architects, designers, and property owners.

Why Indoor Air Quality Matters

People in Singapore spend an estimated 90 per cent of their time indoors, whether in homes, offices, schools, or commercial buildings. The quality of the air in these spaces directly affects health, cognitive performance, and comfort.

Poor indoor air quality is associated with a range of health effects:

• Short-term: Headaches, eye irritation, throat discomfort, fatigue, and difficulty concentrating. These symptoms are sometimes grouped as Sick Building Syndrome.
• Long-term: Respiratory conditions, allergic sensitisation, and chronic irritation of the mucous membranes. Some volatile organic compounds are classified as carcinogens with long-term exposure.
• Productivity impact: Research shows that improved indoor air quality correlates with measurable increases in cognitive function and work output, making it a business performance issue as well as a health concern.

In Singapore’s context, the Building and Construction Authority (BCA) and the National Environment Agency (NEA) both address indoor air quality through building codes and guidelines. Green building certifications, including BCA Green Mark, include specific criteria for indoor air quality that are directly influenced by material selection.

How Interior Materials Affect Air Quality

The primary mechanism by which interior materials affect air quality is through the emission of volatile organic compounds (VOCs). These are carbon-based chemicals that evaporate at room temperature, releasing gases into the indoor environment.

Sources of VOC Emissions

Common interior material sources of VOC emissions include:

• Flooring: Some vinyl flooring products, laminate, and carpet can emit VOCs, particularly formaldehyde, from adhesives, backing materials, and surface treatments.
• Wallcovering: Printed wallpapers and vinyl wallcoverings may release compounds from inks, plasticisers, and adhesive layers.
• Adhesives and sealants: The products used to install flooring and wallcovering can be significant VOC sources, sometimes exceeding the emissions from the finish materials themselves.
• Fabric: Curtains, upholstery, and carpet fibres may be treated with flame retardants, stain repellents, or anti-microbial agents that off-gas over time.
• Furniture: Composite wood products, foam cushioning, and surface finishes in furniture contribute to the overall VOC load.

Emission Patterns

Most interior materials exhibit highest VOC emissions immediately after installation, with levels declining over days to weeks. This initial period, often called the off-gassing phase, is why newly renovated spaces often have a noticeable chemical odour. However, some compounds continue to emit at lower levels for months or years, contributing to chronic exposure.

In Singapore’s climate, high temperatures and humidity can accelerate VOC emissions from certain materials, making the selection of low-emission products even more important than in temperate climates.

Specifying Low-VOC Flooring

Flooring covers the largest surface area in most interiors and is therefore a primary focus for indoor air quality management.

When specifying flooring for healthy indoor environments, look for:

• Third-party emission testing: Products tested to standards such as GREENGUARD Gold, FloorScore, or the French A+ emission rating provide verified low-emission performance.
• Phthalate-free formulations: Some older vinyl flooring products use phthalate plasticisers that are now restricted or avoided. Specify products that are explicitly phthalate-free.
• Low-VOC adhesives: Even a low-emission flooring product can compromise air quality if installed with a high-VOC adhesive. Specify adhesives that meet the same emission standards as the flooring itself. Click-lock installation systems that require no adhesive offer the best outcome for air quality.

The flooring collection includes products tested to international emission standards for healthy indoor environments.

Choosing Wallcovering for Healthy Interiors

Wallcovering selection affects air quality through both the product itself and the adhesive system used for installation.

Product Emissions

Low-VOC wallcoverings are manufactured using water-based inks, non-toxic pigments, and minimal chemical treatments. Non-woven wallcoverings made from natural or recycled fibres typically have lower emissions than heavily processed synthetic alternatives.

For healthcare and education projects where air quality standards are strictest, specify wallcoverings with GREENGUARD Gold certification, which tests for over 10,000 individual chemical compounds and sets emission limits that are safe for sensitive populations including children and the elderly.

Adhesive Systems

Wallcovering adhesives are a frequently overlooked source of indoor VOCs. Specify adhesives that meet low-VOC standards and are specifically recommended by the wallcovering manufacturer. Some wallcovering products use paste-the-wall systems that require less adhesive overall, reducing emissions.

Explore wallcovering options with documented low-emission performance for your projects.

Fabric and Soft Furnishing Considerations

Fabrics contribute to indoor air quality through the treatments and finishes applied during manufacturing. While the base fibres themselves, whether natural or synthetic, are generally low-emitting, the chemical treatments added for performance, including flame retardancy, stain resistance, and anti-microbial properties, can be sources of VOCs and other airborne contaminants.

Strategies for healthy fabric specification include:

• Choose OEKO-TEX certified fabrics: The OEKO-TEX Standard 100 tests for harmful substances in textiles and certifies that the product is safe for human contact.
• Prefer inherently flame-retardant fibres: Fibres such as modacrylic and certain polyesters achieve flame retardancy through their chemical structure rather than added treatments, eliminating the off-gassing associated with topical flame retardant chemicals.
• Specify water-based fabric treatments: When stain resistance or other treatments are required, water-based formulations emit fewer VOCs than solvent-based alternatives.
• Ventilate after installation: New curtains and upholstery should be aired in a well-ventilated space before installation, or the room should be ventilated at a higher rate for the first few days after installation.

Best Practices for Healthy Interior Environments

Beyond individual product selection, several project-level practices improve indoor air quality outcomes.

• Specify comprehensively: Address emissions from all interior materials, not just one or two categories. A low-VOC floor paired with high-VOC adhesives and untested wallcovering undermines the effort.
• Request documentation: Require emission test reports and safety data sheets for all specified materials. Generic claims of being “eco-friendly” or “green” are insufficient without third-party verification.
• Plan the installation sequence: Install high-emission materials first and allow adequate ventilation time before installing soft furnishings that can absorb VOCs from other sources.
• Commission air quality testing: For sensitive projects such as healthcare facilities, schools, and childcare centres, commission post-installation indoor air quality testing to verify that emission levels meet the project’s health targets.
• Maintain ventilation: Ensure the HVAC system provides adequate fresh air ventilation rates in accordance with SS 554 (Singapore Standard for indoor air quality) to dilute any residual emissions from interior materials.

Final Thoughts

Indoor air quality and interior material choices are fundamentally linked. Every product specified for a building’s interior either contributes to or detracts from the health of the air occupants breathe. In Singapore’s sealed, air-conditioned buildings, this relationship is amplified.

The good news is that low-emission alternatives exist for every interior material category. Specifying them requires attention, documentation, and a commitment to occupant health that goes beyond ticking certification boxes.

Book an appointment with our design consultants to discuss low-emission material options for healthier interiors.