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



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

 disulfide 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 OF SACKED PEANUTS IN FREIGHT CARS 



Concerns resorting to freight-car fumigations of shelled sacked 

 peanuts while the commodity is sidetracked at some transfer point 

 can get the same protection more cheaply by insisting upon receiv- 

 ing from the railroad modern tight steel cars and fumigating the 

 loaded cars on their own siding overnight. For this purpose hydro- 

 cyanic acid gas should be used at the rate of 1 pound of liquid hydro- 

 cyanic acid or its equivalent per 1,000 cubic feet of car space. Experi- 

 ments have shown that in steel cars loaded according to common 

 practice this gas gives good control when the ventilators and doors 

 are well sealed. Fumigations in wooden cars are less satisfactory, 

 and in very loosely constructed cars of little value. 



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 



Eeturned 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; methyl formate- 

 carbon dioxide mixtures, 30 pounds; chloropicrin, 2 pounds; liquid 

 hydrocyanic acid or its equivalent, 8 ounces; or methyl bromide, 1 

 pound. 



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 



