I read the article, "Controlling dust with mineral oil," (see World Grain, May 2000, page 18) with a feeling of resignation. I was an outspoken critic of the practice in the 1980s and remain a critic today, but feel like a fish swimming upstream.
I can certainly understand why the elevators like it:
1. It is cheap.
2. It is effective.
3. Most important, it allows them to sell the "dust" to flour mills and other processors, who then have the task of removing it to produce a wholesome food for you and the consuming public.
My experience has been that the addition of oil hurts milling results, and I remain convinced of that today. However, that is not my primary objection to the use of it. My primary objections are twofold:
First, grain dust is not the innocuous substance described in your article. Rather, it is a very nocuous substance consisting of fungi, bacteria and other mycotoxins, pollen, dust spores, insects, insect fragments and insect excreta, as well as small particles of grain.
To confirm this, I personally caught numerous samples of wheat screenings (i.e. grain dust) at Dixie Portland elevators in the 1980s. Invariably, the samples were heavily contaminated with insects and insect fragments – not the kind of material you want in your bread, crackers or cookies.
Second, there is no control on the use of oil for dust control. Nobody knows how many times the grain is treated or what kind of oil is being used. I am sure that most elevators are responsible in this area, but history shows that any time there is no control of a process, there invariably are abuses.
I find it ironical that your article appeared at a time when the wheat producers are trying to get the U.S. Department of Agriculture to subsidize grain cleaning equipment at the export elevators. That is because U.S. wheat is dirty by world standards and no one wants to buy it when they can get much cleaner wheat from our competitors.
I don't believe it is a coincidence that as the use of oil has grown these past 20 years, the reputation of U.S. wheat has deteriorated and our exports have steadily dropped.
Robert G. Reid
The Mennel Milling Company,
Fostoria, Ohio, U.S.