The difference between hydrocarbons and volatile organic compounds
VOCs vs. Hydrocarbons: What the Differences Mean for Air Quality
Tracking volatile organic compounds, or VOCs, is an accepted means of improving air quality. Whether at home or in professional settings, people use devices that take VOC measurements in standardized units to understand how their environments might impact their health. But what about other dangerous chemicals?
Before they can truly take control of the air they breathe, consumers need to understand the facts about the substances that place them in harm's way. This quick guide breaks down some of the distinctions.
Organic Chemistry Basics
Volatile chemicals are those likely to change into gases. Compared to compounds like water, these substances evaporate with far greater ease, which means they can quickly contaminate indoor air.
An organic chemical is a substance that contains carbon, but many carbon-bearing molecules are excluded from this definition for various historical and technical reasons. For instance, although some smart indoor air quality monitors track substances like carbon dioxide and carbon monoxide, these chemicals aren't VOCs.
Volatile chemicals have many sources. For instance, carbon tetrachloride is primarily made by companies that use it to produce chemicals like chlorofluorocarbons, or CFCs. Although it's a banned chemical (1), it still may occur in some consumer products. Dichloromethane, or methylene chloride, is both chemically volatile and hazardous in its normal liquid form yet not grouped with VOCs.
Hydrocarbons
Hydrocarbons, which include many organic compounds derived from fossil fuels, exclusively contain hydrogen and carbon atoms. While hydrocarbons are known for their evaporative tendencies, not all organic compounds are volatile, and some chemically volatile substances aren't classified as exposure hazards by the government. The potential confusion surrounding these terms makes it even wiser for consumers to start tracking air quality and emissions.
Some of the most dangerous volatile organic chemicals pose multiple threats, such as polycyclic aromatic hydrocarbons, or PAHs. These organic chemicals, which feature rings of carbon atoms, are massive problems near combustion sources, such as backyard grills and cigarettes. Thanks to their known role in causing various forms of cancer, PAHs are heavily regulated worldwide.
The Air Quality Implications
Understanding VOC concentration trends in the atmospheric environment on one hand, and inside homes and offices on the other hand, is a smart way to start improving people's health. PAH and VOC concentrations can shift based on a variety of factors. For instance, VOC emissions from building materials may be more likely in specific weather conditions, and many hazardous construction products can cause exposure problems throughout their entire lifetimes (2).
Indoor air quality and VOC go hand-in-hand: High concentrations typically indicate conditions that are prone to accumulate pollutants of all kinds. Although VOC emission levels aren't the only thing that people should be concerned with, they're good hallmarks of general air quality for those seeking to get healthier.
Sources
(1) https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/risk-evaluation-carbon-tetrachloride
(2) http://www.inive.org/medias/ECA/ECA_Report18.pdf
