INDUSTRIAL FUMIGATION AGAINST INSECTS 53 



chinery is stopped can be omitted. Each piece of machinery is 

 treated separately, and in addition the open space of the mill is 

 treated at the rate of 1 pound of chloropicrin per 1,000 cubic feet. 



Sufficient data have not yet been obtained for making definite rec- 

 ommendations of dosages to fit the varying conditions encountered in 

 general mill fumigation. As a rule, however, the following dosages 

 recommended by the manufacturers of chloropicrin will give satis- 

 factory results : 



Dosage Table for Treating Milling Machinery 



All bins, including packer bins, feed and bran 



bins, and screening bins 1 pound per 1,000 cubic feet. 



Elevator legs 8 to 9 ounces each, in up- 

 stream side. 



All reels, purifiers, dusters, scourers, and con- 

 veyors 5 to 6 ounces each. 



Square sifters 2 to 3 ounces each. 



Rolls 1 ounce each. 



Separators 2 to 3 ounces each. 



Flour agitators 1 2 ounces each. 



Grinders for screenings and bran 2 ounces each. 



Buhr mill 2 ounces. 



The proper quantity of chloropicrin for each floor of the mill 

 should be measured out from the 100-pound cylinders into quart glass 

 bottles or gallon containers and distributed before the fumigation is 

 begun. The measuring should be done outside the building so that 

 the fumes will be dissipated in the open air. The quart bottles 

 should be graduated so that the correct dosage for each piece of ma- 

 chinery can be applied quickly. One pound of chloropicrin equals 

 dy 4 fluid ounces. 



The fumigators start at the top of the mill and work down, treat- 

 ing all the machinery and leaving the elevator boots until the. last. 

 Each fumigator must wear a mask equipped with a canister espe- 

 cially adapted to protect against the vapors of chloropicrin. 



The machinery is treated by sprinkling from the quart bottle di- 

 rectly inside each machine or, if this is impractical, by pouring it in 

 through a hole in one end. Aluminum sprinkler corks can be at- 

 tached to the bottles as they are used. In open mill space the 

 chloropicrin is sprinkled on burlap sacks spread out on the floor, 

 6-quart sprinkling cans being convenient for this purpose. 



Care should be taken not to spatter the liquid on the hands or feet, 

 since it might cause blistering of the skin. 



Where conditions in the mill do not warrant a general fumigation, 

 satisfactory results can sometimes be obtained by fumigating the 

 machinery only. For this type of fumigation the chloropicrin is 

 applied directly into the machines in accordance with the dosage 

 table. The dosage for the reels and purifiers should be increased in 

 proportion to the quantity of stock left in the machinery. In gen- 

 eral, at least 1 pound should be used in each machine. 



Considerable time is required to ventilate a building that has 

 been fumigated with chloropicrin, as evaporation is slow and the 

 fumigant clings to commodities with great tenacity. When present 

 in flour, chloropicrin has a deleterious effect on its baking quality, 

 but this effect disappears when the flour is aerated. 



