INDUSTRIAL FUMIGATION AGAINST INSECTS 



27 



FUMIGATION WITH METHYL BROMIDE-CARBON DIOXIDE 



MIXTURES 



A mixture of methyl bromide and carbon dioxide has recently been 

 placed on the market as a fumigant for use in vacuum chambers, at- 

 mospheric vaults, and tight storage rooms. It is sold in steel pressure 

 cylinders containing 50 pounds at 15 cents, f. o. b. shipping point. 



Methyl bromide is noninflammable and has a boiling point of 

 40.1° F. It is a gas at ordinary room temperatures. It is similar 



Figure 26. — Battery of 10 cylinders of ethylene oxide-carbon dioxide mixture attached to 

 manifold, heaters, and distributing pipes connecting with storage vaults (not shown) 

 in room. In lower background is a 6- by 8- by 10-foot metal fumigation vault, which 

 opens into the room beyond. 



to ethylene oxide in that the killing effect is delayed. Methyl bromide 

 is poisonous to human beings, 3 since after absorption by the body it 

 breaks down forming methanol, which continues to accumulate in the 

 body as long as the exposure persists. Severe poisoning by methanol 

 results after prolonged exposure to concentrations of methyl bromide 

 too small to exhibit an anesthetic action; hence workmen should not 

 be exposed to appreciable concentrations of the gas. 



The dosages recommended vary with the commodity to be fumi- 

 gated, but under ordinary atmospheric conditions the usual dosage is 

 1.5 to 20 pounds of the mixture per 1,000 cubic feet for an exposure of 

 24 hours. 



The fumigant is discharged into the atmospheric fumigation cham- 

 ber or storage room in the form of a slush or snow or as a gas. It 



3 Henderson, Y., and Haggard, H. W. noxious gases, p. 159. New York. 1927. 



