The following is a brief excerpt from Andrew Pace’s new book, ‘Building For Health’:
“….the acronym VOC stands for volatile organic compound. VOC-based marketing is a false premise. Paint companies that use marketing claims about VOC content are exploiting a common misunderstanding about the relationship between VOC content and safety. For a variety of reasons I will discuss, Homeowners often falsely associate low VOC content with safety. Marketing claims about VOC content should be completely disregarded due to a lack of definiteness as to their meaning.
VOC-based marketing
First, the Federal Trade Commission has successfully prosecuted claims that paint companies played too fast and loose with their VOC-based marketing. Namely, paint companies have made claims about VOC content in tinted paints that are only valid for base paints. Additionally, paint companies have made untested VOC based claims about VOC contents during both the application and use phase. In the same advertising, at least one company made implicit claims as to the relationship between VOC content and safety, while implying particular safety benefits to pregnant women and children. These cases and their associated advertisements suggest that paint companies are keenly aware of this false premise and seek to exploit it for marketing purposes.
Unclear definition of VOC
Second, the definition of a VOC is unclear when used in paint marketing. In chemistry, a VOC refers to a volatile organic compound. Each of those three words means something very specific. The volatility of a compound refers to its tendency to evaporate eagerly at low or moderate temperatures. In chemistry jargon, we might say that a volatile substance has a high vapor pressure (i.e. evaporates eagerly) and a low boiling point (i.e. evaporates at low or moderate temperatures). The organicness of a compound refers to the presence of carbon atoms in the compound. In other words, the O in VOC merely suggests that the chemical compound has a carbon atom and that one might study it in organic chemistry class. The word compound is merely a synonym for a chemical or a molecule. A chemical’s classification as a VOC has no relationship to its inhalation toxicity, which is all I care about when discussing the safety of paints. For example, the VOC in vodka (ethyl alcohol) is generally safe to inhale, while the VOCs in gasoline (benzene, toluene, ethylbenzene, and xylene) are extremely toxic. Organic compounds are distinguished from inorganic compounds. Common inorganic compounds include many acids, bases, salts, and metals. Common organic compounds include nutrients, alcohols, and fuels. This concludes my discussion of the purely chemistry based definition of a VOC.
More clarity
When we read marketing statements related to VOCs, it is un clear whether or not we are reading a statement based on the chemistry definition or the regulatory definition. A prominent regulatory definition of VOCs comes from the Clean Air Act. The regulatory definition is oriented towards the reduction of ground level ozone (i.e. smog) to protect ambient air quality. A VOC that does not react to ultraviolet light will necessarily not contribute to smog. This is why the Clean Air Act specifically exempts non-photochemically reactive compounds from VOC regulation. These non-smog-producing compounds are called exempt compounds. Paint companies are required to disclose the regulatory VOC content of paints in grams per liter on product labels. Accordingly, the regulatory VOC content of a paint only captures the content of non-exempt VOCs. A paint company that can leverage the regulatory definition of a VOC to achieve a regulatory VOC content of zero grams per liter will likely also market that product as “zero VOC”. The smog-producing ability of a specific VOC has no direct relationship with the safety of that VOC as an ingredient in a building material. Propylene glycol (PG) is an example of a non-toxic solvent that is both a chemical VOC and a regulatory VOC. (Roll-on deodorants can be more than 50% PG by weight.4) Therefore, we as homeowners should disregard claims about the low or nil VOC content of paints on the basis that they are not directly related to safety…”
Get the book and learn more!
The entirety of the chapter on paints goes into great detail about the use of biocides and other additives which are not captured by VOC regulations, as well as my personal recommendations. I encourage you to get you copy of the book to lean more.