Circular 21 - Insecticides and Subsidiary Materials 50 
I\Oi;THYL BROMIDE 
Methyl bromide is used as a fumigant 
for the control of storage pests in modern 
concrete or brick warehouses of tight con- 
struction because of its ability to penetrate 
closely-packed products. Excellent results 
can be obtained even if a v/arehouse is loaded 
with food supplies, whole grains, or feeds. 
It should not be used, hov/ever, to fumigate 
flour or other milled cereals, or products 
high in fat content, since these products may 
retain harmful quantities of residual bromides. 
The method of application is discussed in 
Circular 22, pp. 20-23 and 37. 
IJethyl bromide is also used extensively 
for the fumigation of plants and plant products 
in connection v/ith the enforcement of insect 
quarantine regulations. It may also be em- 
ployed as a fuiaigant in the control of fleas 
in situations where it is necessary to kill 
rats, mice, and other rodents which harbor 
these pests, 
I.Iethyl bromide, OH^Br, is a gas at 
summer temperatures, and is about 3i times 
heavier than air. It has a boiling point of 
40.1° F. and belov; this tei:iperature is a 
heavy, colorless, liquid v.liich is but slightly 
soluble in water. It is freely soluble, 
however, in alcohol, chloroform, ether, and 
carbon disulfide. It \.as originally used as 
a fire extinguisher and has been used in 
refrigeration. The gas is non-inflauimable, 
very penetrating, and is poisonous, v.hich 
makes it of value as a fumigant. As commer- 
cially produced it is of a purity of 99i 
Dercent or better. 
