2 BULLETIN- 681, U. S. DEPARTMENT OF AGRICULTURE. 
In June, 1913, an explosion in a feed-grinding plant in Buffalo, 
N. Y., caused the death of 33 men, injured more than 70 employees, 
and damaged a great deal of grain and property. Shortly afterwards 
the Bureau of Chemistry began its work in connection with dust 
explosions in grain mills, elevators, and industrial plants. During 
the period in which this study has been carried on a large number of 
disastrous dust explosions, in which many lives have been lost, 
large quantities of grain and food products destroyed, and much 
property damaged, have occurred in grain elevators, feed, cereal, and 
flour mills, starch factories, sugar refineries, and other industrial 
plants which handle grain. Several definite causes for these explo- 
sions have been established, and effective preventive methods have 
been developed and tested. At present the United States Depart- 
ment of Agriculture is conducting a special war-emergency campaign 
for the prevention of dust explosions and fires. Representatives of 
the department are rendering direct assistance to the millers and 
grain men of the country in installing devices for preventing ex- 
plosions and in showing them how to remedy dangerous conditions. 
The grain-dust explosion work, as conducted by the Bureau of 
Chemistry, falls into two general classes: 
(1) Dust explosions which occur in grain mills, elevators, and 
industrial plants during the handling and milling of grains and the 
manufacture of food products. 
(2) Dust explosions which occur in thrashing machines during the 
operations in the harvest fields. 
MILL AND ELEVATOR EXPLOSIONS. 
As soon as possible after the occurrence of an explosion in a mill or 
elevator, the field engineers of the bureau investigate carefully the 
conditions under which the explosion originated and assist the 
company to devise and install some means for preventing any more 
such explosions. During the course of these field investigations it 
has become apparent that one of the causes for a large number of 
dust explosions and fires in the cereal and feed mills, particularly in 
the feed-grinding departments, is the ignition of the dust on the 
interior of the grinding machine during operation. In many 
instances the evidence indicated that the explosion and fire originated 
within the machine, usually in the attrition type of mill. As they were 
believed to have been caused by sparks from foreign particles or me- 
tallic substances entering with the grain, the bureau emphasized the 
necessity for taking steps to remove these materials from the mill 
stream before it entered the grinding machines. 1 
i Preliminary Report on the Explosibility of Grain Dusts, Cooperative Investigation by Millers Com- 
mittee, Buffalo, N. Y., under the direction of Dr. George A. Hulett, chief chemist, Bureau of Mines, TJ. S. 
Department of the Interior, by David J. Price, engineer in charge, and Harold H. Brown, assistant 
chemist, Grain-Dust Explosion Investigations, Bureau of Chemistry, U. S. Department of Agriculture 
Copies no longer obtainable. 
