Roasted Coffee Beans and Carbon Monoxide Emissions
Coffee bean grinding and storage can be a source of carbon monoxide. It is not expected that small quantities of coffee beans are an issue.
Where Does the Carbon Monoxide Come From?
Roasting coffee beans involves chemical reactions which release volatile compounds. These include the compounds responsible for the aromas of roasted coffee beans as well as carbon monoxide and carbon dioxide.
The internal structure of roasted coffee beans contain many pores or voids. These pore spaces increase with the degree of roasting (the longer and hotter roast cause darker beans which have more internal pore space).
As coffee beans are roasted, some of the carbon monoxide and carbon dioxide becomes trapped in the pores of the coffee bean.
After the beans are roasted, these gases are released from within the bean to the environment until they are in equilibrium with the environment.
Rate of Release
The speed of this gas release depends on the surface area. This means that ground beans will release gases much faster than whole beans.
Carbon Monoxide Health Effects
Carbon monoxide is invisible odorless and tasteless. It is easily absorbed through the lungs into the blood stream where it attaches to red blood cells. This stops the transport of oxygen throughout the body. At low concentrations, headaches, dizziness and nausea are all common. At high concentrations death can occur quickly.
Conclusion
When large amounts of beans are ground carbon monoxide release can reach levels that are harmful and potentially fatal. Contact K2 environmental hygienists to do a risk assessment. Ventilation is a key control.
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