26 



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



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

 valves can be opened without the use of a gas mask, 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 

 released into the room from the outside. The cylinders are all 

 equipped with fittings that can be connected with the piping system 

 (fig. 27). 



Where the floors are painted or varnished, the cylinders should be 

 placed in shallow pans or on several thicknesses of newspaper, to 

 prevent damage in case the liquid should run down the sides of the 

 cylinder. 



Figure 26. — Cylinders of ethylene oxide-carbon dioxide mixture being emptied auto- 

 matically by the pressure of carbon dioxide within. 



This mixture is very effective in rooms that are nearly airtight, 

 but it should not be used in rooms that are loosely constructed. 



After the fumigation and ventilation all that is necessary is to roll 

 the empty cylinders out of the room and return them to the owner. 



FUMIGATION WITH METHYL FORMATE-CARBON DIOXIDE 



MIXTURES 



Warehouses and storage rooms that are thoroughly modern in 

 construction can be fumigated with mixtures of methyl formate and 

 carbon dioxide. Ordinarily these mixtures are used only in special 

 fumigation vaults. The value of methyl formate as a fumigant was 

 first established by the experimental work of this Department. 

 Alone, its vapors are explosive and inflammable in the presence of 

 fire in any form; hence, mixtures with carbon dioxide have been 

 developed, the vapors of which are entirely free from the fire and 

 explosion hazard. 



