INDUSTRIAL FUMIGATION AGAINST INSECTS 39 



feet for a period of from 1 to 2 hours gives satisfactory results at a 

 cost of from 3% to. 4 cents per 100 pounds of nuts. A mixture of 

 carbon disulphide and carbon dioxide has been used in the vacuum 

 treatment of nuts, but owing to the need for special equipment for 

 applying it safely and to the fact that it is unsuitable for the 

 treatment of pecans, Brazil nuts, and cashews, it is not recommended. 



FUMIGATION SCHEDULE FOR CANDY FACTORIES 



The adoption of a regular fumigation schedule would largely 

 eliminate insect losses in the candy industry. Infested raw materials 

 and returned goods constitute the main sources of infestation in the 

 factory. Insects from these sources spread all over the factory and 

 lay eggs on the finished product. These eggs hatch after the candy 

 is packed and produce costly infestations in packages that leave the 

 factory apparently in good condition. 



Every candy factory should have a fumigation vault or a vacuum 

 chamber, and all returned goods should be fumigated before they are 

 admitted to the factory. All incoming raw materials that are sus- 

 ceptible to insect attack, such as nut meats, cocoa beans, farinaceous 

 materials, dried fruits, milk powders, and chocolate, should be rigidly 

 inspected on their arrival at the plant and, if infested or suspected 

 of being infested, should be fumigated before being placed in the 

 main storage sections. If possible, raw materials should be stored 

 away from the main part of the factory, and in sections that are 

 adapted for separate fumigation. 



DOSAGES 



Returned goods and raw materials other than nut meats can be 

 fumigated in tight vaults with one of the following fumigants at the 

 dosages indicated per 1,000 cubic feet: Ethylene oxide, 2 pounds; 

 ethylene oxide-carbon dioxide mixture, 20 pounds; or liquid hydro- 

 cyanic acid or its equivalent, 8 ounces. 



Large storage sections can best be fumigated with hydrocyanic 

 acid at the rate of 8 ounces of liquid hydrocyanic acid or its equiva- 

 lent per 1,000 cubic feet. 



As a general precaution it is advisable to fumigate the entire fac- 

 tory at least once a year. For this purpose hydrocyanic acid should 

 be used at the same rate as for the treatment of the large storage 

 sections. 



FURNITURE 



Insect-infested furniture is usually fumigated in an atmospheric 

 vault, although a vacuum vault can be used and is preferable in 

 cases where infestation is due to wood-boring insects. 



Hydrocyanic acid, ethylene oxide, ethylene oxide-carbon dioxide 

 mixture, carbon disulphide, chloropicrin, carbon tetrachloride, and 

 the ethylene dichloride-carbon tetrachloride mixture can all be used 

 for the fumigation of furniture in atmospheric vaults. 



Hydrocyanic acid and the ethylene dichloride-carbon tetrachloride 

 mixture are used most commonly. A dosage of 8 ounces of liquid 

 hydrocyanic acid or its equivalent, or of 14 pounds of ethylene di- 

 chloride-carbon tetrachloride mixture, per 1,000 cubic feet of space, 

 for a period of 12 to 24 hours will give satisfactory results unless 



