INDUSTRIAL FUMIGATION AGAINST INSECTS 



27 



The methyl formate-carbon dioxide mixtures are sold at 10 cents 

 per pound, f. o. b., in steel pressure cylinders containing' 50 pounds. 

 The liquid is discharged under its own pressure. When used in con- 

 nection with vault fumigation, the cylinder is set on platform scales 

 close to the vault wall, through which the desired dosage is dis- 

 charged into the vault by means of easily made metal connections. 

 When the scales indicate that the required poundage has been dis- 

 charged, the cylinder valves are closed. 



The mixture is discharged as a fine mist, which immediately 

 vaporizes. The vapors seem to be harmless to food and other com- 

 modities thus far treated, and they are only slightly toxic to man as 

 he ordinarily comes in contact with them in fumigation work. The 



Figure 27. — 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. 



recommended dosage, per 1,000 cubic feet of empty space, is 28 

 pounds, with an exposure of from 12 to 24 hours. Several mixtures 

 have been offered to the public, but one containing about 15 percent 

 of the methyl formate seems to be the most effective and safe. This 

 fumigating mixture is similar to the ethylene oxide-carbon dioxide 

 mixture in the manner in which it is marketed and used. 



VAULT FUMIGATION 



Many establishments have use for a small fumigation vault for 

 the treatment of incoming raw materials, returned goods, outgoing- 

 products, etc. Such a vault may be constructed of any material that 

 can be made erastight or reasonably so. 



