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Chapter VI. Materials
Chapter VI.
Every surface, finish, and furnishing in a home is also a small chemical environment.
Paints release solvents as they cure. Engineered wood products can emit formaldehyde from their binders. Upholstered furniture may contain flame retardants that gradually migrate into household dust. Vinyl flooring can release plasticizers for years after installation.
Individually, these exposures are often small. But they are continuous and cumulative, and they occur in the spaces where people spend the majority of their time.
Material health, the practice of evaluating building materials for their chemical composition and emissions behavior, is therefore one of the most direct ways interior design influences human health. The products specified for a home do more than determine how a space looks; they shape the quality of the indoor environment throughout the life of the building.
Why Materials Belong in the Design Brief
The interior of a typical home contains hundreds of manufactured chemical products, many introduced to meet practical performance requirements such as durability, fire resistance, stain resistance, and cost efficiency.
Historically, however, the regulatory system governing these chemicals has lagged behind scientific understanding of their health effects. In the United States, the Toxic Substances Control Act (TSCA) was not significantly updated until 2016, and many chemicals currently used in consumer and building products have never undergone comprehensive long-term safety testing.
For designers, this means product selection carries an implicit health dimension.
The difference between a conventional MDF panel and one manufactured without added formaldehyde, or between a paint independently certified for low emissions and one that merely claims to be low-VOC, can measurably influence the air quality of the finished space.
These decisions are rarely dramatic. They are routine specification choices—but they can have lasting consequences for the indoor environment.
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Primary Contributors
Several categories of chemicals appear frequently in residential materials and have been the focus of substantial environmental health research.
Formaldehyde is a volatile organic compound used in adhesives and binders for particleboard, medium-density fiberboard (MDF), and some plywood products. It is classified as a known human carcinogen and can off-gas continuously from composite wood products, particularly when new or exposed to heat and humidity.
Flame retardant chemicals are often added to upholstered furniture foam, textiles, and certain children’s products to meet flammability standards. Some compounds in this category, particularly organohalogen and organophosphate flame retardants, can migrate into household dust, where they may be ingested through routine hand-to-mouth contact. Research has linked certain flame retardants to endocrine disruption, developmental effects, and cancer risk.
Plasticizers (phthalates) are chemicals used to soften polyvinyl chloride (PVC), commonly found in vinyl flooring, wall coverings, and flexible plastics. These compounds are semi-volatile, meaning they slowly migrate into both indoor air and dust. Epidemiological studies have associated certain phthalates with reproductive and developmental health concerns.
Per- and polyfluoroalkyl substances (PFAS) are often applied as stain-resistant or water-repellent treatments on carpets, rugs, and upholstery fabrics. Known as “forever chemicals,” they resist degradation and can accumulate in the environment and the human body over time. Some PFAS compounds have been linked to immune suppression, thyroid disruption, and certain cancers.
Volatile organic compounds (VOCs) include a broad range of solvents and chemicals present in paints, adhesives, sealants, and coatings. Short-term exposure can cause eye and respiratory irritation, headaches, or dizziness, while long-term exposure to certain VOCs may affect neurological function.
Where Design Makes a Difference
Material health is primarily managed through informed product specification.
Several certification frameworks help designers evaluate the chemical transparency and emissions performance of building materials.
The Declare label, developed by the International Living Future Institute, functions much like a nutrition label for building products. Manufacturers disclose ingredients above a defined threshold and identify whether the product contains substances on the Living Building Challenge Red List, a catalog of chemicals considered particularly hazardous.
GREENGUARD Gold certification, administered by UL Solutions, verifies that a product’s emissions meet strict limits for total VOCs and individual chemicals. Testing is performed in environmental chambers designed to simulate conditions in a furnished room.
In practice, material health decisions often begin with the highest-exposure surfaces.
Flooring covers the largest continuous area of most interiors and comes into frequent contact with occupants, especially children. Selecting hardwood with water-based finishes, natural linoleum, cork, or porcelain tile avoids the plasticizer emissions associated with many vinyl flooring products.
Cabinetry and built-in millwork should ideally be specified with no-added-formaldehyde (NAF) or ultra-low-emitting-formaldehyde (ULEF) panels.
Paints and coatings should carry independent emissions certifications, rather than relying solely on manufacturer claims of low-VOC content.
Intervention Points
Material health is easiest to manage when specification criteria are established early in the project rather than evaluated product by product.
A typical material health protocol might include:
Requiring GREENGUARD Gold or equivalent certification for finishes installed in occupied spaces
Specifying NAF or ULEF composite wood panels for cabinetry and millwork
Avoiding PVC-based flooring and wall coverings where practical
Selecting upholstered furniture that complies with TB 117-2013 without organohalogen flame retardants
Declining stain-resistant treatments that rely on PFAS chemistry
These criteria are not as restrictive as they might appear. Over the past decade, the market for health-conscious building materials has expanded significantly, and compliant products are available at nearly every price point.
The designer’s role is simply to know what questions to ask, understand the available certifications, and explain these choices to homeowners in a way that is clear, measured, and grounded in evidence rather than alarmism.
A Realistic Standard
Eliminating all chemical exposure within a home is neither possible nor necessary. Many materials that contain synthetic chemicals serve important functions in durability, moisture resistance, and safety.
The goal instead is to reduce unnecessary exposure, particularly to chemicals that have strong evidence of harm at levels commonly encountered in residential environments.
Several organizations provide structured frameworks for evaluating building products, including the Health Product Declaration Collaborative, the Cradle to Cradle Products Innovation Institute, and the WELL Building Standard’s Materials concept.
For homeowners, the key idea is simple: the materials in a home are not inert. They interact with the indoor environment throughout their entire service life.
Choosing materials thoughtfully is therefore not just an aesthetic decision, it is a long-term investment in the health of the space and the people who live within it.
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Sources & Further Reading
International Living Future Institute — Declare Product Label — https://declare.living-future.org/
UL Greenguard Gold Certification — https://www.ul.com/resources/ul-greenguard-certification-program
Health Product Declaration Collaborative — https://www.hpd-collaborative.org/
International WELL Building Institute — Materials Concept — https://v2.wellcertified.com/en/wellv2/materials
U.S. Environmental Protection Agency — Formaldehyde — https://www.epa.gov/formaldehyde
Cradle to Cradle Products Innovation Institute — https://c2ccertified.org/
Silent Spring Institute — Household Exposure Research — https://silentspring.org/
Consumer Product Safety Commission — Flame Retardants — https://www.cpsc.gov/
Agency for Toxic Substances and Disease Registry — PFAS — https://www.atsdr.cdc.gov/pfas/