INDUSTRIAL FUMIGATION AGAINST INSECTS 



49 



disulphide should not be used unless the vault is isolated from the 

 rest of the buildings and the fire hazard can be controlled. The 

 fumigation of an entire tobacco warehouse with carbon disulphide 

 is a dangerous procedure and is not recommended. 



For the vacuum fumigation of tobacco (figs. 30 and 31) the follow- 

 ing dosages per 1,000 cubic feet are recommended : 8 Ethylene oxide- 

 carbon dioxide mixture, 60 pounds for 4 hours or 55 pounds for 15 

 hours for imported cigarette types ? 50 to 55 pounds for 4 hours or 

 45 to 50 pounds for 15 hours for cigar-filler, 65 pounds for 4 hours 

 or 60 pounds for 15 hours for cigar-wrapper, and 45 pounds for 4 

 hours for manufactured cigars; liquid hydrocyanic acid, 5 pounds 



Figure 40. — Tobacco in bales and stacked as closely as shown here cannot be fumigated 

 satisfactorily by ordinary atmospheric fumigation. The bales should be either more 

 loosely stacked or removed to vacuum chambers for fumigation. 



for 4 hours or 4 pounds for 15 hours for imported cigarette types, 4 

 pounds for 4 hours or 3.5 pounds for 15 hours for cigar-filler, and 5 

 pounds for 4 hours or 4.5 pounds for 15 hours for cigar- wrapper 

 tobacco. 



FLOUR 9 



For controlling insects in flour mills and reducing insect damage 

 to milled products, some form of fumigation is usually practiced. 

 Many millers are satisfied with one general fumigation a year, others 

 may supplement the general fumigation with local or spot fumiga- 

 tions, while some find it profitable to have several general fumiga- 

 tions a year in addition to a regular schedule of local fumigations. 



8 In private communication from W. D. Reed, in charge of the Stored Tobacco Insects 

 Laboratory at Richmond, Va. 



9 Further information on the fumigation of flour mills may be obtained from Circular 

 390. revised. Flour Mill Insects and Their Control. 



