If you’re reading this article, chances are you are familiar with volatile organic compounds (VOCs), chemicals emitted from products into the surrounding air. Perhaps you even know that choosing zero- or low-VOC products is a good first step in selecting healthier building materials. But did you know that products labeled as zero- or low-VOC can still contain hazardous volatile compounds or other chemicals of concern?
What is a VOC anyways?
VOC stands for volatile organic compound. The term “organic” in this case refers to a chemical with at least one carbon-hydrogen bond, which can be found in most plant, animal, and petroleum based materials. The term “volatile” means it is possible for those chemicals to evaporate, or get into the air. We care about VOCs because when they become airborne, they have the potential to be inhaled and negatively impact human health.
Globally, regulatory definitions of VOCs vary. For example, the European Union defines a VOC as a chemical with a boiling point of ≤ 250°C at standard atmospheric pressure.1 The US Environmental Protection Agency (EPA) regulatory definition of a VOC is more nuanced: “..any compound of carbon, including carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates and ammonium carbonate, which participates in atmospheric photochemical reactions, except those designated by EPA as having negligible photochemical reactivity.”2 Did we lose you? The reason this definition is relatively more complex is because the regulation was intended specifically to prevent smog formation in outdoor air.
The EPA’s list of exempt volatile compounds includes chemicals that have negligible photochemical reactivity – meaning they are not likely to create ozone (the main component of smog) when released into the air – and are therefore not considered VOCs per the EPA.3 Inclusion on the exempt list does not mean that the chemical has been tested and found to be of low concern to human health and the environment. It ONLY means that the chemical is not expected to contribute to smog formation. Yes, that’s right, smog - that last sentence is worth one more read through.
The EPA itself acknowledges that this definition of VOC may cause confusion for consumers looking to protect indoor air quality. As they note, “While it is probably prudent to use products with lower VOC levels [indoors], it does not assure that the products are any better (and they may even be worse) than products with higher VOC levels.”4 They suggest that VOCs exempt under their regulatory definition should not be “excluded from consideration for indoor air."5 Essentially, this means the EPA recommends considering the broader human health impacts of the exempt VOCs before using them.
Low-VOC ≠ Low Hazard
While it is important to avoid chemicals that can contribute to smog formation, it is also important to understand the human health and environmental hazards of chemicals. Of the exempt chemicals, just under half have a high or very high concern for ozone depletion potential and/or global warming potential. Several have high or moderate concern for carcinogenicity - meaning they have the potential to cause cancer. Other exempt chemicals impact the developing fetus or the body’s hormonal system. For example, tetrachloroethylene is on the EPA’s exempt VOC list and is a known carcinogen and developmental toxicant.6
This is far from a theoretical problem. Our work here at HBN has found products marketed as low-VOC that include hazardous volatile chemicals. Our research on Low-VOC Solvent-based TPO/EPDM Roofing Membrane Adhesive, for example, found that some VOC-compliant products contained a fluorinated solvent, 1-Chloro-4-(trifluoromethyl)benzene (PCBTF). This solvent is a halogenated organic compound that the International Agency for Research on Cancer (IARC) has classified as possibly carcinogenic to humans.7
What does it mean when a product is labeled “Low-VOC”?
It is important to understand that Low-VOC or Zero-VOC labels and certifications are not standardized. Some labels refer to the VOCs emitted from the product; others are based on the VOC content as defined in regulations set forth by the EPA8 or state agencies such as California’s South Coast Air Quality Management District (SCAQMD).9 Product literature such as data sheets that list the amount of VOC in the product are most often relying on the regulatory definition of VOCs, in which certain VOCs are exempt and therefore not counted. This is how a product labeled as “Zero VOC” and with VOCs reported as 0 g/l may actually contain volatile compounds. Therefore, it is always recommended to look for labels and certifications concerned with indoor air quality in addition to selecting products that are labeled Low- and Zero-VOC.
In addition to “Low-VOC” labels, look for indoor air quality certifications.
While there are a variety of testing certifications that address indoor air quality, the most robust certifications are based on the California Department of Public Health (CDPH) Standard Method v1.2 (sometimes referred to as CDPH v1.2 or CA Section 01350).10 This test method looks at a list of 35 VOCs that are known to cause chronic health effects and measures the amount of each that is emitted from individual products. To be certified, products cannot emit chemicals above a threshold concentration that is considered unhealthy for people in schools and office buildings. Common programs and certifications you may see that incorporate this test method include:
- SCS Indoor Advantage Gold Certified - Indoor Advantage Gold certification requires CDPH v1.2 VOC emissions testing by an approved list of third-party laboratories.11
- ClearChem - ClearChem is a program that allows manufacturers to make valid self-declarations about products conforming to CDPH v1.2 VOC emissions testing.12
- Intertek Certified Clean Air GOLD - Clean Air GOLD Certification requires VOC emissions testing by Intertek to certify that products meet certain green building standards, including CDPH v1.2.13
- GREENGUARD Gold Certified - GREENGUARD Gold certification requires CDPH v1.2 VOC emissions testing by Underwriters Laboratories (UL) and also measures several additional chemicals and particles in the air.14
Remember, Low- and Zero-VOC labels are a good thing. Reducing the use of chemicals that contribute to smog formation is a vital part of eliminating harmful pollutants in the air we breathe. Programs and certifications such as those noted above address additional ways that VOCs can negatively affect our health in the indoor environment.
Prefer fully disclosed, fully assessed products
Information on VOCs is only one of several variables to consider when assessing the health of materials. Products may contain other hazardous chemicals that are not VOCs.
Look for products that have a public Health Product Declaration (HPD) or Declare Label. An HPD is a voluntary open standard for manufacturers to disclose product contents and associated health hazards. You can check whether or not a product has an HPD in the HPD Public Repository. Determine if the product record is fully disclosed – by “fully disclosed” we mean products with public HPDs that have all contents characterized, screened, and identified to 100 ppm (parts per million). In addition, prefer those products whose public content disclosure has been verified by a third party when available. There are also product certification initiatives, like Declare, which is a product transparency program run by International Living Future Institute (ILFI) that compares products against ILFI’s established list of worst in class chemicals they call the “Red List”. Look for products with Declare labels here.
Because very few of the tens of thousands of chemicals in use have been fully assessed for health hazards, there is a great need for expansion of publicly available hazard assessments. A “fully assessed” product is one for which all chemicals and materials in the product have been assessed by the GreenScreen for Safer Chemicals, ChemFORWARD, or a similar hazard assessment tool, and the assessments have been made publicly available. The GreenScreen is a globally recognized, transparent methodology for assessing chemical hazard that supports identifying and benchmarking chemicals of concern and identifying safer alternatives. ChemFORWARD hosts a chemical hazard and safer alternatives database that is populated and updated by licensed toxicologists using a comprehensive, globally accepted methodology.
Products with fully assessed chemical content disclosure allow consumers to understand what chemicals are in the products they are selecting and how those chemicals may affect human health.
How to select the best
Depending on the product type or installation method, here are some ways that you can ensure you are choosing the best material option:
- Avoid site-applied liquid products when possible. For example, avoid adhesives by using mechanically installed flooring and roofing.
- Where site-applied liquid products are needed, prefer water-based products over solvent-based products, even low-VOC solvent-based products. HBN’s Product Guidance may assist you in selecting products that are generally safer including those that don’t rely on volatile ingredients in the first place.
- Prefer products with a Health Product Declaration (HPD) or a Declare label. These documents disclose the product content, and in the case of HPDs, give you insight into hazards associated with disclosed content.
- Prefer products with ingredients that are fully assessed for hazards and safer alternatives such as a GreenScreen for Safer Chemicals or a ChemFORWARD Chemical Hazard Assessment.
- Look for programs and certifications designed to assess indoor air quality, such as those outlined above.
At this time in the US, consumers cannot rely on regulations to guarantee product safety with regard to indoor air quality because there are simply very few regulations that address indoor air quality. As the EPA notes, “Even if we had authority to regulate indoor air quality, it would be difficult to regulate household (or other) products because we have no authority to collect information on the chemical content of products in the marketplace (nor does any Federal Agency).”
Fully disclosed and fully assessed product content is the only way to be absolutely certain there are no hazardous chemicals in the products you use. However, because this information is not always available, HBN provides Product Guidance based on our research into the chemicals and components most commonly used in a variety of building product types. Where fully disclosed and fully assessed products are not available, you can use this guidance to compare product types and make a safer, healthier choice based on HBN’s comprehensive, science-backed research.
As consumers, we have the power to influence manufacturer disclosure by preferring products that do not use hazardous chemicals and have full content disclosure. We encourage you to share your healthy materials preference with your manufacturer supplier and always request content disclosure where absent.
 European Union Publications Office. Directive 2004/42/CE of the European Parliament and the Council. EUR-Lex. https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32004L0042&rid=10#:~:text=Purpose%20and%20scope&text=The%20purpose%20of%20this%20Directive,the%20formation%20of%20tropospheric%20ozone.
 The US Environmental Protection Agency. 40 CFR Part 51.100.
 The US Environmental Protection Agency. Volatile Organic Compound Exemptions. https://www.epa.gov/ground-level-ozone-pollution/volatile-organic-compound-exemptions.
 The US Environmental Protection Agency. Does EPA regulate volatile organic compounds (VOCs) in household products?
 The US Environmental Protection Agency. Technical Overview of Volatile Organic Compounds. https://www.epa.gov/indoor-air-quality-iaq/technical-overview-volatile-organic-compounds#definition.
 International Agency for Research on Cancer (IARC) Monographs - 106. Tetrachloroethylene. https://monographs.iarc.who.int/wp-content/uploads/2018/06/mono106-002.pdf.
 International Agency for Research on Cancer (IARC). Some Industrial Chemical Intermediates and Solvents. Volume 125. https://publications.iarc.fr/_publications/media/download/6078/af7feb19033c4766201daaa114f044096cce5051.pdf.
 The US Environmental Protection Agency. 40 CFR Part 51.100.
 The South Coast Air Quality Management District Rule 102. https://www.aqmd.gov/docs/default-source/rule-book/reg-i/rule-102-definition-of-terms.pdf?sfvrsn=4.
 CDPH/EHLB. Standard Method for the Testing and Evaluation of Volatile Organic Chemical Emissions from Indoor Sources Using Environmental Chambers Version 1.2. January 2017. https://www.cdph.ca.gov/programs/ccdphp/deodc/ehlb/iaq/cdph%20document%20library/cdph-iaq_standardmethod_v1_2_2017_ada.pdf.
 SCS Global Services. Indoor Air Quality Certification. https://www.scsglobalservices.com/services/indoor-air-quality-certification.
 ClearChem™ Transparent Self-Declared Claims. https://www.berkeleyanalytical.com/working-us/clearchem-self-declared.
 Intertek Group plc. VOC Indoor Air Quality Certification. https://www.intertek.com/certification/indoor-air-quality/.
 Underwriters Laboratories (UL). What Does "GREENGUARD Certified" Mean? https://www.ul.com/insights/what-does-greenguard-certified-mean#:~:text=GREENGUARD%20Certification%20means%20the%20product,even%20stricter%20standards%2C%20Steady%20says.