Many folks worldwide live in constant fear of chemicals. High up on the list are volatile organic compounds (VOCs), such as hydrocarbons, which vaporize easily. VOCs come from gasoline combustion and from evaporation of liquid fuels, solvents, and organic chemicals such as those in some paints, cleaners, nail polish remover, soaps, pesticides, and even we humans.
Here are a number of everyday emitters of VOCs:
The smell of a pine forest comes from a VOC named alpha-pipene. 1
Do you like the leathery, plasticky aroma that hits you when you slide behind the wheel of a new car? If so, you are enjoying a complex mixture of VOCs, primarily alkanes and substituted benzenes along with a few aldehydes and ketones. 2
Do you enjoy a nice glass of wine? If so, do you realize that the bouquet and entry from a newly opened bottle partly depends on the relative assortment of VOCs in the wine? 3
VOCs have been detected in drinking water. 4
Foods and beverages are loaded with VOCs, which proivde a flavor fingerprint that helps humans and animals recognize appropriate foods and avoid poor or dangerous food choices. More than 7,000 flavor volatiles have been identified and catalogued from foods and beverages. 5
Another large source the medical community has long recognized is that humans exhale volatile organic compounds. The major VOCs in the breath of healthy individuals are isoprene (12- 580 parts per billion, ppb), acetone(1.2-1,880 ppb), ethanol (13-1,000 ppb), methanol (160-2,000 ppb). Minor components include pentane and higher aldehydes and ketones. There are also several other compounds that appear to be present from 1 to 10 ppm in breath, including 1,1,1-trichloroethane, butane, cis-and trans-2-butene, 2-hexene, n-butyl alcohol, isobutyl alcohol, capryl alcohol, methyl isobutyl ketone, butyl acetate, ethyl benzene, indene, pentanal, and propanal. Add heavy smoking and high occupational exposure to the mix and the list grows. 6
Now, a recent discovery about VOCs that could change the way regulators act has appeared. Cars and trucks have historically pumped out most of the VOCs, along with other pollutants such as nitrogen oxides. But significant levels of VOCs also escape from household and commercial products, according a to a study published in Science on February 15. Everyday items such as soaps, perfume, paint and pesticides now contribute as heavily to certain sorts of air pollution in US cities as cars and trucks. 7
“The things I use in the morning to get ready for work are comparable to emissions that come out of the tailpipe of my car,” says Brain McDonald, an air pollution researcher a the US National Oceanic and Atmospheric Administration (NOAA) in Boulder, Colorado, who led the work. “I think that's what surprises a lot of people.” 8
Transport derived emissions of VOCs have decreased owing to stricter controls on air pollution. This means that the relative importance of chemicals in pesticides, coatings, printing inks, adhesives, cleaning agents, and personal care products has increased. McDonald et al. Show that these volatile chemical products now contribute fully one-half of emitted VOCs in 33 industrialized cities. Thus, the focus of efforts to mitigate ozone formation and toxic chemical burdens need to be adjusted. Existing US regulations on VOCs emphasize mitigating ozone and air toxins, but they currently exempt many chemicals that lead to secondary organic aerosols. 7
McDonald reports that a notable change in emissions may be underway in US cities with effects on secondary pollutants such as organic aerosols. Shifting from an urban atmosphere dominated by transport related VOCs to one dominated by VOCs from coatings, adhesives, and consumer products would alter predictions of urban air quality and challenge the existing policy framework for emissions control.
Does this mean that regulations for household products are imminent? If so, what about all the food we eat and all the breaths of the billions of folks on this earth? Will will also regulate these?
References
Jeannie Allen, “Chemistry in the sunlight,” ChemMatters, 21, 22, Oct. 2003
Steve Ritter, “New car smell,” Chemical & Engineering News, 80, 45, May 20, 2002
Steven T. Lund, and Joerg Bohlman, “The molecular basis for wine grape quality- a volatile subject,” Science, 311, 804, Feb. 10, 2006
Julian B. Andelman, “Total exposure to volatile organic compounds in potable water,” Henk Maarse, Editor, (New York, Marcell Dekker, 1991)
Stephen A. Goff and Harry J. Klee, “Plant volatile compounds: sensory cures for health and nutritional value?”, Science, 311, 815, Feb. 10, 2006
J. D. Fenske and S. E. Paulson, Journal of Air & Waste Management Association, 49, 594, 1999
Brian C. McDonald et al., “Volatile chemical products emerging as largest petrochemical source of urban organic emissions,” Science, 359, 760, Feb. 15, 2018
Jack Dini is author of Challenging Environmental Mythology. He has also written for American Council on Science and Health, Environment & Climate News, and Hawaii Reporter.
Many folks worldwide live in constant fear of chemicals. High up on the list are volatile organic compounds (VOCs), such as hydrocarbons, which vaporize easily. VOCs come from gasoline combustion and from evaporation of liquid fuels, solvents, and organic chemicals such as those in some paints, cleaners, nail polish remover, soaps, pesticides, and even we humans.
Here are a number of everyday emitters of VOCs:
