LIBRARY 
STATE PLANT BOARft 
May 1944 
URITED STATES DEPARTMENT OF AGPJCuLTURE 
Agricultural Research Administration 
Eureau of Entomology and Plant Quarantine 
METHYL BROMIDE 
A REVIEW OR 
LS AR IRSECT RUMIGRRT-- 
LITEPATURE THROUGH 1940 
E-618 
By R. L. Busbey, Division of Insecticide Investigations 
Properties of Methyl Bromide 
Methyl bromide (CHjBr) as used in fumigation is a colorless gas 
with a slight sweetish odor similar to that of ether low-molecular- 
v/eight alRyl halides. It has the following physical constants: 
Molecular weight — — — — — 94.95 
Boiling point — — i& .---. ,-- 3 56° C. 
Melting point -—-08 93.66° C, 
Specific gravity oV, iquid 1.732 °/0 ° C. 
Specific grivity oi as -- 3.28 at 20° C. and 
760 mm. compared 
with air under the 
same conditions 
It is very slight^ soluble in -water and with cold water forms a white 
crystalline hydrate of the approximate formula CR3Br.20 HoO, It is 
soluble in the common organic solvents. It is noninflammable and in 
mixture with air can be exploded by a spark only within the narrow 
range of 13.5 to 14.5 percent by volume of methyl bromide. 
This compound has been used for years by the chemical industry 
as a methylating agent in the preparation of dyes and antipyrine. It 
has been employed to some extent as a fire-extinguishing a^ent, either 
alone or mixed with other materials such as carbon tetrachloride. It 
has found limited use also as a refrigerati -.;nt in mechanical re- 
fri gerators. 
The insecticidal possibilities of methyl bromide were first report- 
er 1 \)\r Le Goupil (63) in 1952. Since that time it has been tested ex- 
tensively and is now widely used in the fumigation of nursery sto< , 
fruits, seeds, bulbs, stored grain, arid vegetables to destroy certain 
insects against which quarantines have been estal , I has a] so 
been used tc some extent a? nhouse . Durin - 1! 
probably 400,000 pounds of 1 bromide were used as an insecticidal 
fumigant in the united States. An important use also is as a rodonti- 
cide. 
Methyl bromide possesses a nv i ' nt. It 
is highly toxic to many kinds of all stares of • ~t. 
It is stable chemically and in the con- ions use' has no deleter- 
ious effect on most plant tissues. It ' s no objectionable taste 
or odor to foodstuffs fumigated vdth it and 1< -ous residue. 
It is convenient to handle, since it is readily liquefied and yet vapor- 
izes at temperatures encountered in fVunigat: . It is the onl; on 
