CONTROL OF INSECTS ATTACKING STORED TOBACCO 31 



Warranted by the assured: 



1. That not exceeding 1 pound of carbon disulfide for each 100 cubic feet, 

 interior space, will be used in the fumigation of any building or compartment. 



2. That all carbon disulfide, on storage, will be kept in metal, preferably zinc 

 lined and sealed receptacles ; and that these receptacles will be kept detached at 

 least 50 feet from all main buildings, or buildings where open fires or lights are 

 maintained. 



3. That no open fires or lights will be allowed in any building subject to 

 fumigation with carbon disulfide. 



4. That all electric and telephone wires entering any building subject to 

 fumigation with carbon disulfide will be equipped with outside control switches, 

 enclosed with lock boxes, and that these switches will be opened and locked 

 during the entire period of fumigation. 



5. That no artificial heat of any description will be allowed in any building 

 or compartment subject to fumigation during the period of fumigation. 



6. That any or all buildings or compartments which are under fumigation will 

 remain closed for a period of at least 24 hours, and when opened, following 

 fumigation, will be thoroughly ventilated for a period of at least three hours 

 before being used. 



7. That when a building or compartment is fumigated all doors shall be 

 locked and the keys turned over to one reliable and responsible person in charge. 



VACUUM CHAMBERS 



The fumigation of tobacco at a pressure below that of the atmosphere 

 for the elimination of all stages of the cigarette beetle and the tobacco 

 moth was first introduced into the tobacco industry several years ago. 

 The apparatus has been modified and adapted for tobacco fumigation, 

 and during the past few years many improvements have been made. 

 The fumigation of tobacco in partial vacuum is the most efficient 

 method known of applying the gases available for use on tobacco. 

 Vacuum chambers should be installed in tobacco warehouses for the 

 fumigation of incoming lots of infested tobacco, both imported and 

 domestic types, for storage and also for the fumigation of tobaccos en 

 route to the factory. 



APPARATUS AND PROCEDURE 



The apparatus required consists of a steel cylinder of sufficient 

 strength to withstand the pressure when a partial vacuum is produced 

 inside. Attached to the cylinder is a pump of suitable size, a volatilizer 

 for the gas, and the necessary recording gages. A part of the equip- 

 ment consists of loading platforms and conveyors built especially to 

 accommodate the containers of tobacco to be fumigated. The chambers 

 are made in both cylindrical and rectangular shapes and are capable 

 of holding various quantities of tobacco up to one or more carload lots. 



The tobacco to be fumigated is placed in the steel chamber, the doors 

 are closed, and the pressure is reduced by pumping out the air until a 

 vacuum of 28 to 29 inches is registered on a standard vacuum gage. 

 The total amount of vacuum produced depends upon the barometric 

 pressure outside. The proper dosage of fumigant is then applied by 

 weighing it into the vacuum tank. At the end of the exposure the gas 

 should be pumped out of the tank and the pressure restored to normal 

 by breaking the vacuum with air. This is called "air washing" and 

 may be repeated one or more times if desirable. The manufacturers 

 of vacuum chambers can supply estimates and specifications to meet 

 the needs of individual factories and warehouses (fig. 22) . 



