As environmental and health concerns become increasingly important, the impact of materials on the environment and human health has become a crucial consideration in material selection for construction projects beyond traditional factors like performance, aesthetics, and quality. With people spending most of their time indoors, the concentration of chemical emissions in indoor air can be significantly higher. As a result, indoor air quality has gained greater importance in recent years.
Green building rating systems, such as LEED, BREEAM, and WELL, have varying criteria for Indoor Air Quality. These criteria are evaluated by independent organizations using various standards for different types of materials.
People can be exposed to chemicals through three different routes: inhalation, ingestion, and skin contact. Of these, exposure to chemicals through inhalation is the most common and a major source of concern, as indoor air quality in homes, offices, schools, and other indoor environments can be up to five times more polluted than outdoor air. This is due to the presence of chemical volatile organic compounds (VOCs) which can be harmful to human health. Hence, the assessment of indoor air quality has become increasingly important.
Chemical emissions, also known as Volatile Organic Compounds (VOCs), are carbon-based chemicals that evaporate into the air at room temperature. These emissions can have both immediate and long-term effects on human health.
It's important to note that these health effects can persist even after the source of the chemical emissions has been eliminated. Other indoor pollutants, such as ozone, gases from combustion, cigarette smoke, pesticides, radon, and mold, can also have adverse health effects but are typically not related to building materials.
To improve indoor air quality, various strategies can be implemented, with a focus on source control. This can include the use of materials with low VOC emissions, such as low-emission pressed wood furniture, low-emission paint, or varnish. This helps to reduce indoor air pollution without consuming additional energy or increasing energy costs.
Additionally, increasing ventilation can also bring in the fresh air, reducing indoor pollutants. Advanced heating and cooling systems with energy recovery devices can bring in more fresh air from outside. The use of air purification systems and devices can also help improve indoor air quality by reducing particles and specific indoor pollutants. However, for the device to be effective, regular maintenance is necessary, and performance specifications should be in accordance with the manufacturer's specifications.
The growing importance of Indoor Air Quality has led to an increased focus on the use of low-emission materials by manufacturers. This is also reflected in green building rating systems such as LEED certification, which require the testing of materials like paints, primers, silicones, and adhesives against California standards. The California Green Building Standard Code is considered the most comprehensive regulation for residential and commercial green buildings in the United States. It plays a key role in setting VOC limits for indoor and outdoor building materials, and maximum formaldehyde emission limits for composite wood products such as plywood, particleboard, and fiberboard. These limits are based on standards developed by the California Air Resources Board (CARB).
In green building rating systems like LEED, building materials must undergo testing to ensure they meet VOC emission requirements. If the material passes the VOC content test using the LEED v4 (SCAQMD Rule 1113 method) and the chemical emission test using the Standard Method for the Testing and Evaluation of Volatile Organic Chemical Emissions from Indoor Sources Using Environmental Chambers (CA 01350), it will be indicated in the report results.
Materials that must undergo VOC testing for green building projects include:
The purpose of 'Indoor Air Quality,' which is one of the LEED Credit Categories, is to reduce the carcinogens that can be found indoors, to provide indoor air quality, to provide daylight and scenery to the building users, to provide indoor air quality, thermal, lighting, visual and acoustic comfort. A credit to this category is 'Low Emission Materials.' This loan aims to minimize the chemicals (VOC-chemical volatile organic compounds) that are given out by the materials used in the interior, to increase the health and productivity of the employees and building users during the construction, and to reduce the environmental damages. Contributes up to 3 points.
Option 1: Product category calculation: If 3 of 7 material categories are provided, 1 point can be obtained, 2 points if five are provided, and 3 points if six are provided.
Option 2: Budget calculation method: Floor, ceiling, wall, thermal and acoustic insulation, furniture (may be out of scope), outdoor products.
Volatile Organic Compounds (VOCs) are chemicals commonly found indoors in products such as paint, cleaning supplies, building materials, and furnishings. Some of the most common VOCs found indoors include:
Formaldehyde: a common ingredient in adhesives, resins, and textiles
Benzene: found in plastics, synthetic fibers, rubber, and detergents
Toluene: commonly found in paint, adhesives, and solvents
Xylene: commonly used as a solvent in printing, rubber, and leather industries
Ethylene glycol: a common ingredient in antifreeze and brake fluid
Acetone: a common solvent in nail polish removers and cleaning products
Methylene chloride: found in paint strippers, adhesives, and cleaning products
These VOCs can have negative impacts on indoor air quality and can cause health problems such as headaches, nausea, dizziness, and respiratory irritation. Reducing exposure to these chemicals is important for maintaining good indoor air quality.
BTEX compounds, including benzene, toluene, ethylbenzene, and xylene, are a group of volatile organic compounds commonly found in petroleum products like gasoline and used as solvents in various industrial and consumer products. They are the most common indoor pollutant and are known to have negative impacts on air quality and human health. Long-term exposure to BTEX compounds can cause serious health problems, including damage to the blood system and organs such as the kidney and liver.
Phenol, found in building materials, cleaning products, disinfectants, and cigarette smoke, can cause eye and respiratory irritation and in severe cases, convulsions, circulatory failure, and other health problems. Although the US EPA classifies phenol as not carcinogenic, the International Agency for Research on Cancer lists it as a substance known to be non-carcinogenic to humans.
Glycol Ethers, a type of Ethylene Glycol, are used as solvents and additives in various paints, primers, adhesives, and cleaning products. Exposure to glycol ethers can cause eye and respiratory irritation and long-term exposure can result in severe liver and kidney damage. The US EPA and the International Agency for Research on Cancer classify glycol ethers as potentially non-carcinogenic, but the State of California designates them as substances with developmental and reproductive toxic effects.