26 



CIRCULAR 3 6 9, U. S. DEPARTMENT OF AGRICULTURE 



Fumigation With Ethylene Oxide-Carbon Dioxide Mixture 



Warehouses and. storage rooms that are of modern tight construc- 

 tion can be successfully fumigated with a mixture of ethylene oxide 

 and carbon dioxide. This mixture is put up in cylinders in the 

 proportion of 1 part by weight of ethylene oxide to 9 parts of carbon 

 dioxide. It leaves no obnoxious odor or poisonous residue on the 

 commodity fumigated. The mixture is sold in 30- and 60-pound 

 cylinders. It is noninflammable and not highly toxic to human be- 

 ings, but high concentrations have an anesthetizing effect. Con- 

 centrations of more than 10 percent with carbon dioxide must also be 

 avoided. 



The application of the ethylene oxide-carbon dioxide mixture is 

 exceedingly simple. The requisite number of cylinders are placed 



Figure 22. 



-Cylinder of ethylene oxide-carbon dioxide mixture being emptied 

 automatically by the pressure of carbon dioxide within. 



in the room to be fumigated and the valves opened. The pressure 

 of the carbon dioxide automatically discharges the contents of the 

 cylinders in the form of a very fine mist, which vaporizes at once 

 (fig. 22). A cylinder of the mixture will empty itself in about 5 

 minutes after the valve has been opened wide. 



When the valves are opened wide, the force of the escaping gas 

 often causes the cylinders to topple over. Ta avoid this, the cylin- 

 ders can be lashed to the walls of any stationary object, or several 

 cylinders can be lashed together with the discharge vents pointing 

 in opposite directions. 



Unless a large number of cylinders are used in a fumigation, the 

 valves can be opened without the use of a gas masjj:, although it is 

 not advisable to stay in a strong concentration of the gas for any 

 appreciable length of time. Before starting the fumigation it is 

 well to see if the valves on all the cylinders can be opened easily by 

 hand ; any that are stuck should be loosened with a wrench. 



If desirable, a storage room can be piped in the same manner as 

 for liquid hydrocyanic acid, and the ethylene oxide-carbon dioxide 



