Thank you for a very interesting article on the use of mineral oil in the
control of grain dust. This is a subject dear to the heart of anyone involved in the handling of grain and feed. I have a couple of questions. First, is the use of mineral oil for this purpose allowed in the U.K.? Second, can mineral oil be used on soybean meal, gluten, etc?
West Twin Silos, Ltd.
Editor's reply: We asked Thomas Wulfers, product technology manager at Lyondell-Citgo, Houston, Texas, U.S., to respond to Mr. Orr's questions. He writes:
Using mineral oil for dust control on soybean meal and gluten is not recommended because those products are too fine in texture and the oil tends to gum the surface. As for using mineral oil for grain dust control in the U.K., that answer is more complicated.
Basically, the test requirements to establish the quality of food grade white mineral oils in the U.S. are set by the United States Pharmacopoeia. The U.K. equivalent of the U.S.P. is the British Pharmacopoeia. The quality of food grade white mineral oils as established by these two agencies is essentially identical.
The conditions for the safe use of food grade white mineral oils in food in the U.S. are set by the U.S. Food and Drug Administration. The F.D.A. has established that food grade white mineral oils of any viscosity can be safely used at a maximum level of 200 ppm as a dust control agent for wheat, corn, soybean, barley, rice, rye, oats, and sorghum, and that high viscosity (>8.5 cSt @ 100°C) food grade white mineral oil can be safely used at a maximum level of 800 ppm as a dust control agent for rough rice.
The U.K. equivalent of the F.D.A. for this purpose is the British Ministry of Agriculture, Fisheries and Food. In February 1989, M.A.F.F. proposed to ban the use of mineral hydrocarbons in food except in chewing compounds and food packaging materials. The justification of the proposed ban was that there were inadequate toxicological studies. However, M.A.F.F. has delayed the implementation of the ban while new toxicological studies are underway.
In the meantime, the Mineral Hydrocarbons in Food Regulation, passed by M.A.F.F. in 1966, is the only existing U.K. food regulation for white mineral oil. Under that regulation, mineral hydrocarbons are prohibited for use in food except for the rind of whole, pressed cheese and chewing compounds. In 1995, this regulation was amended under the Miscellaneous Food Additives Regulations to allow mineral hydrocarbons in certain food additives.
On the whole, using mineral oil for grain dust control has not been practiced in Europe or the U.K.
Editor's note: Dr. Ken Wildey of M.A.F.F.'s Central Science Laboratory said grain does fall under the category of "food." The Food Act of 1990, amended in 1995, clearly states that grain is a food once it is in storage for future human consumption. Hence, under the 1966 regulation, it is prohibited to apply mineral oil to grains intended for human consumption. Mr. Wildey said he was not aware of any legal impediment that would prevent the use of mineral oil on grain that is to be used as animal feed.
Dr. Wildey said he knew of some companies in the U.K. that were experimenting with this practice on feed grain for export, mainly to reduce dust nuisance to nearby residential properties. This is a relatively new, unpracticed concept in the U.K., and as Niq Pietrzyk of the M.A.F.F.'s Arable Crop Division said, "I'm afraid there is a paucity of information on this issue."
By far, the application of food-grade white mineral oil to grain as a dust suppressant has been largely concentrated in the U.S. and in Canada. Check with your own national agencies for specific mineral oil regulations.