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



Bagged flour is fumigated with difficulty owing to the great absorp- 

 tion of the gas by the outer layers of flour." Schenk 7 found that satis- 

 factory results could be obtained with 140-pound bags of flour by 

 using a dosage of 3 pounds of liquid hydrocyanic acid per 1,000 cubic 

 feet of space for 24 hours at 70° F. The bags should be separated 

 from one another in the vault by means of racks. 



For packaged cereals a dosage of 2 pounds of liquid hydrocyanic 

 acid or its equivalent, or 30 pounds of the ethylene oxide-carbon di- 

 oxide mixture, per 1,000 cubic feet of space should be used for a 

 oeriod of 24 hours. 



SAFEGUARDS TO BE EMPLOYED IN FUMIGATION 



WORK 



In all fumigation work the person in charge should not only ac- 

 quaint himself with the clangers involved, but should bring his 

 assistants together and explain to them the need for caution, and 

 what should be done in case difficulty arises. He should know the 

 first-aid recommendations issued by the manufacturers of the par- 

 ticular fumigant he is about to use. He should employ only men 

 known to be dependable. Members of the fumigating crew should 

 be in good physical condition, with minds alert so that the}^ can act 

 calmly and rapidly and work together according to a prepared and 

 rehearsed plan of procedure. They should abstain from the use of 

 intoxicants. They should take no chances. 



All persons except fwmigators should leave the building. — When 

 an entire building, or any floor, is to be fumigated, all persons in 

 the entire building should be notified in advance and told that they 

 must leave the building between certain specified hours. In large 

 establishments the owners should be held responsible for keeping- 

 persons out of a building unless they have a definite agreement with 

 the fumigator that he assume all responsibility connected with the 

 safe conduct of the fumigation. 



It is not always necessary, or desirable, for persons to leave certain 

 buildings while vaults or similar limited areas are under fumiga- 

 tion. Much depends upon the fumigant used, the type of building, 

 and the methods employed for ventilation. The informed fumigator 

 is in a position to determine what action is necessary. Many routine 

 vault fumigations are conducted daily in congested city areas with- 

 out danger to human life. 



Danger signs should be posted. — Placards calling attention to the 

 fact that a fumigation is being conducted and warning persons to 

 keep out should be posted on all outside doors of the building. 



Guards for buildings are desirable. — Guards should be stationed 

 outside buildings to make certain that they are not heedlessly entered 

 while being fumigated with a dangerous vapor. 



Gas masks should be available. — Gas masks should always be worn 

 during fumigation with hydrocyanic acid gas, chloropicrin, or any 

 other quickly fatal fumigant. Ethylene oxide, methyl formate, 

 ethylene dichloride, carbon disulphide, and carbon tetrachloride, 

 either alone or in the combinations usually recommended for fumi- 

 gation work, are regarded as only slightly toxic to man as he ordi- 



Private communication. 



