Fumigation of raw beans is often required to eliminate the possibility of importing coffee plant diseases into a territory. The most notorious example of this necessity is the state of Hawaii being the only place in the world where Broca and leaf rust do not occur. This state must protect its agricultural product against hitchhiking bugs. To do so, all green coffee that enters the Islands must be fumigated.
But What Is Fumigation?
It is a process in which the green beans are sealed in a container and a fumigant is inserted in the chamber. The gas usually used for coffee is called methyl bromide, and is considered a category 1 ozone depleting gas under the Montreal protocol of 1992. Methyl bromide is highly toxic and humans may absorb it by inhalation and by skin exposure.
Fumigation can take place either in the country of origin or upon arrival to the receiving country. If a shipment is fumigated just before being sent overseas, it must rest for 24 hours to make sure there are no gas leaks that may harm the staff before it can be loaded on the ship. A warning sign must also be placed on the container.
Once the fumigation process is over, sufficient aeration must be undertaken to release the toxic substances. In the specific case of coffee which needs venting during transportation, the vents must be unsealed prior to the container being loaded, so it already has to be fully aerated.
Inspections and Phytosanitary Certificates
But do all coffee importations need to be fumigated when they cross borders? The answer is no. For example, Hawaii’s production is sure not to be contaminated because the pests that are killed by methyl bromide don’t exist on the Islands. Hence, no Hawaiian beans are fumigated when leaving the state for the first time. (In the case they are exported to be decaffeinated and are reshipped to Hawaii still raw, they may be fumigated for the trip back home.)
Also, it is important to know that each green bean shipment comes with a phytosanitary certificate from its origin attesting that the product is pest free. Visual inspections are performed on some samples. It is sometimes judged necessary to fumigate some, but not all of them.
What About Methyl Bromide in the Coffee I Drink?
There is no need to worry. Any trace of chemicals used in fumigation – if any are left – will have completely disappeared during the roasting process, and none of it will get inside your cup of coffee or espresso.
However, being such a bad gas for the environment, methyl bromide is called to be replaced as the fumigant of choice, and lots of research is under way to attain that goal, in compliance with the Montreal protocol. Anyway, being a chemical, methyl bromide can never be used on certified organic products.
The next article will talk about an alternative to methyl bromide that may, in the future, give birth to a certified organic way of eliminating pest importation issues regarding green coffee beans.