Materials & Toxicology
Materials & Toxicology is the practice of choosing building products by what they are made of and what they release into the house, using manufacturer disclosure and third-party emissions testing rather than marketing language. It matters in a hot-humid Central Texas home because heat and humidity can increase the rate at which some materials release volatile compounds, and because a tight, mechanically ventilated house makes the choice of interior finishes a more consequential decision than it is in a leaky one. The evidence base is uneven: emissions measurement is well established, while the health significance of many specific low-level indoor exposures is still being worked out.
How a product gets approved
Every specified item passes through the Approved Materials Catalog, and every catalog entry is versioned rather than overwritten.
- [ESTABLISHED]Established
Third-party emissions testing to a recognized chamber method is the strongest routinely available evidence about what a finish releases indoors.
- [EMERGING]Emerging
Full ingredient disclosure is preferred over a certification mark alone, because a mark tells you a threshold was met, not what is in the product.
- [UNVERIFIED]Unverified
Absence of disclosure is treated as unverified. We say the item is undocumented rather than implying it is safe or unsafe.
Curing and sequence
Where wet-applied finishes are used, we schedule application and ventilation so that the highest-emission period happens before occupancy where the schedule allows it.
Language discipline
- [ESTABLISHED]Established
We do not use the phrase toxin-free, and we do not describe a house or a product as non-toxic. We state what was tested, by which method, and what the result showed.
Sources
Primary references for this page. Where a statement is graded Emerging, the source supports the question being open, not a conclusion.
- 1. Volatile Organic Compounds' Impact on Indoor Air Quality — U.S. Environmental Protection Agency
- 2. Formaldehyde Emission Standards for Composite Wood Products (TSCA Title VI) — U.S. Environmental Protection Agency
- 3. Indoor air quality research and chamber test methods — Lawrence Berkeley National Laboratory, Indoor Environment Group
Related reading
Sources we read and work from under this domain. Pointers to the document, not reports of a finding.
- Building scienceBuilding Science for Strawbale BuildingsJohn Straube · Building Science Corporation
- GuidanceLead Renovation, Repair and Painting (RRP) Program RulesU.S. Environmental Protection Agency · U.S. EPA
- GuidanceNIEHS — Children's Environmental HealthNIEHS · NIEHS
- GuidanceILFI Declare Label DatabaseInternational Living Future Institute · ILFI
- GuidanceLiving Building Challenge Red ListInternational Living Future Institute, 2024 · ILFI
- GuidancePharos ProjectHabitable (formerly Healthy Building Network) · Habitable
Last reviewed August 29, 2026. Reviewed and maintained by Sage Co.
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