Posted by Chris O’Brien
Many people concerned about coffee and sustainability are aware of important issues related to organic agriculture, preservation of the forest canopy and bird habitat, and equitable trading partnerships between farmers and importers/roasters/retailers.
But what about air pollution?
Green coffee beans contain a wide variety of chemical compounds including proteins, fats, sugars, dextrine, cellulose, caffeine, and organic acids. Some of these volatize, oxidize, or decompose (i.e. become pollution) as part of the roasting process. Consequently, toxic compounds such as aldehydes (as in formaldehyde), organic acids (such as acetic acid) and acrolein are emitted as a result of the coffee roasting process.
The EPA regulates these emissions according to classes of pollution: particulate matter, volatile organic compounds, organic acids, and natural gas combustion products.
Here’s the EPA’s flow chart of the emissions created by coffee processing.
Okay, so roasting causes emissions, but it looks like a lot of this is particulate matter (PM). PM is basically airborne dust and dirt. Raking leaves creates particulate matter – soil and dust catching air from rustling up the leaves. That doesn’t exactly sound like a problem worthy of much concern. But the smoke from diesel fuel is also PM – that seems a little worse. Smog is also partly comprised of PM. According to the EPA, PM can cause coughing and contribute to asthma and other respiratory problems. But here’s the real kicker: exposure to PM is linked with premature death.
On top of that, coffee roasting also emits volatile organic compounds (VOCs) which is a complicated way of saying all sorts of air pollution. And finally, roasting emits greenhouse gases such as carbon, methane and nitrous oxide.
Here is an EPA chart of coffee roasting emissions in pounds of emissions per ton of coffee roasted. It gives a whole new meaning to the expression “wake up and smell the coffee.” If you’re reading this and you know of any roasters doing something to address emissions, please submit a comment or email me directly using the Contact form on this blog.