Extreme Heat as an Emerging Operational Risk
Heat and material emissions
Evolving environmental conditions, particularly those related to a changing climate, are impacting building materials and increasing risks to human health. Research recently conducted by Chemical Insights demonstrates how new environmental conditions, specifically extreme heat, affect product emissions. When tested at higher temperatures, emissions from many common building materials were found to have higher total VOC (TVOC) and aldehyde concentrations, increasing occupants’ exposure to poor IAQ.
Chemical Insights’ extreme heat research
Chemical Insights’ scientists examined various common building materials rated for both commercial and residential use to assess their emissions.16 The selected materials represented a range of products typically specified for surfaces such as ceilings, walls and floors.1 Emissions from these common building products were analyzed at two different temperatures: an average room temperature of 73°F (23°C), often used as a standard when testing materials for acceptable IAQ, and an elevated temperature of 95°F (35°C), often experienced by vulnerable populations in suboptimal conditions and/or those experiencing power outages in areas of extreme heat.
Each material was isolated and tested for its chemical emissions, independent of any adhesives, substrates or materials required for installation. Standard testing and analysis methods were utilized to ensure accuracy and repeatability. The research aimed to provide a more comprehensive understanding of VOC and aldehyde emissions under emerging indoor environmental conditions facing extreme heat scenarios.
The total concentrations of chemical emissions released from each material were quantified. Effects, if any, resulting from increased temperature were analyzed to evaluate changes in the type and/or level of chemical emissions released. All the tested materials, natural and synthetic, emitted VOCs. With few exceptions, TVOC and aldehyde concentrations were found to be greater at the higher temperature, with varying results. It is important to note that while these materials are commonly used in building interiors, the results can vary significantly due to differences in material composition, meaning not all products of a shared category or type, like nylon carpet, behave the same way.2 Many factors influence emissions, including material composition, construction methods and coatings, as well as environmental factors such as humidity, ventilation rate, temperature and material aging. Work is ongoing to further evaluate the effect of the changing climate on IAQ.
EXTREME HEAT: KEY INSIGHTS
Expensive isn’t always better | The results were not associated with the cost of the material. Inexpensive materials did not necessarily produce higher VOC emissions at room temperature or at an elevated temperature.
Material performance varies | Not all materials performed the same when exposed to a higher temperature. Materials with the highest rate of emissions at room temperature may not have been the materials with the highest rate of emissions at the elevated temperature. This can have implications when selecting materials, identifying that it is important to carefully consider the impact of heat on materials when making project selections.
Vague product claims | Vague product claims, including “low-VOC,” were not always reflective of the overall VOC emissions. Thus, vague terms should not be the sole criteria for selecting building materials when trying to manage IAQ.
Certification systems | Certification systems, such as UL GREENGUARD Certification and the Cradle-to-Cradle Certified® Products Program, have been established to help manage, independently measure and verify the levels of risk associated with building materials.
These systems assess emission rates from materials, providing specifiers and consumers with the opportunity to limit their VOC exposures. Accredited professionals work to meet the criteria for project certifications, ensuring that selected products contribute to achieving suggested standards.
However, this process involves a mix of competing priorities and complex trade-offs, balancing sustainability and wellness targets with cost and durability requirements. Additionally, these systems only typically certify materials at one temperature and humidity setpoint, not several, which does not accurately represent real conditions.
New chemicals of concern
Chemical Insights found that in some cases, new chemicals of concern were detected only at the higher temperature. When tested, these building materials exhibited emissions of irritant chemicals that affect occupants who are more sensitive even at lower concentrations. For example, renal toxicants and per- and poly-fluoroalkyl substances (PFAS), which are not likely to be found naturally in the environment, were identified in some building materials.
In resilient flooring samples, benzophenone and neodecanoic acid were detected at the higher temperature. Unfortunately, depending on the duration and magnitude of exposure, these chemicals can impact human health. Benzophenone is thought to be a carcinogen, an endocrine disruptor and a neurotransmitter inhibitor when ingested,12 but effects from inhalation are unknown at this time due to lack of evaluation. Neodecanoic acid is thought to induce pulmonary inflammation and cause skin and eye irritations,13,14 underscoring the need to expand the testing criteria for third-party certification.
Cumulative effects
To consider the cumulative effects, researchers at Chemical Insights used exposure modeling to assess the total chemical exposure, which sums the concentration levels of each material in a space.15 Several factors affect the cumulative effects.
- Material Selection: As illustrated by the research,16 some materials emit more TVOCs and aldehydes than others. Specifying a material that emits higher concentrations will increase the cumulative effect.
- Exposure to Extreme Heat: Almost all the materials tested demonstrated higher quantities of TVOCs at the higher temperature, significantly increasing total exposure.
- Quantity of the Material Installed: Some materials, like flooring, are installed in larger quantities than others, like millwork. The larger the quantity, the greater the impact on the cumulative effect.
Simple changes can make a significant difference when selecting materials, developing designs and considering solutions to mitigate occupant risk.
