UNITED STATES DEPARTMENT OF AGRICULTURE 
 Bureau of Entomology and Plant Quarantine 
 Washington, D. C. 
 
 B. E. P. Q.--U73 
 
 ADMINISTRATIVE INSTRUCTIONS 
 
 FUMIGATION OF POTATOES BY METHYL BROMIDE AS A CONDITION OF CERTIFICATION 
 OF POTATOES MOVING BY REFRIGERATOR CAR FROM THE AREA 
 LISTED IN REGULATION 5 OF QUARANTINE NO. US 
 
 (Approved April 30, 1933; effective May 2, 193&) 
 
 Regulation 5» Sec. B, paragraph (6) of the Japanese beetle quarantine 
 (No. US) authorizes the issuance of certificates for the interstate move- 
 ment of potatoes via refrigerator car from the area listed in that regula- 
 tion to points outside the regulated areas between June. 15 and October 15 
 when the potatoes have been fumigated in the car, when deemed necessary in 
 the judgment. of the inspector and when the doors and hatches of the car 
 have been tightly closed or adequately screened under the supervision of 
 an inspector. 
 
 TREATMENT AUTHORIZED 
 
 The treatment described herein has been found to be effective against 
 the Japanese beetle and such treatment is authorized as a basis for certifi- 
 cation of potatoes moving to points outside the regulated areas between 
 June 15 and October 15 via refrigerator car when such treatment is carried 
 out under the supervision of an inspector and in a manner satisfactory to 
 him. 
 
 TRSAEffiNT METHOD 
 
 Fumigation of potatoes in dry refrigerator cars with methyl bromide 
 at a dosage of 2 pounds per 1,000 cubic feet of space, including the space 
 occupied by the potatoes and bunkers of the cars, for a period of 2 hours 
 during which time the car shall remain tightly closed with the plugs in 
 place in the ventilator hatches. The temperature within the car when fumi- 
 gated shall be not less than 70°F. Provision shall be made for circulating 
 the mixture of air and fumigant in the car for as long a time as is deemed 
 necessary by the inspector. At the end of the fumigation period the hatches 
 shall be opened, the plugs removed, screen;.: placed in the hatch openings, 
 and the car shipped under standard ventilation. 
 
 In authorizing the movement of potatoes fumigated according to the re- 
 quirements stated above, it is to be understood that no liability shall at- 
 tach either to the United States Deportment of Agriculture or to .any of its 
 employees in the event of injury. 
 
 Caution : Methyl bromide is a gas at ordinary temperatures. It is 
 colorless and practically odorless in concentration used for the fumigation 
 of potatoes. It is a poison, and the operator should use an approved gas 
 mask when exposed to the gas at concentrations used in fumigation, and when 
 opening the hatches for ventilating the cars. The car should not be entered 
 until it is well aerated. AVERY S. HOYT, 
 
 Acting Chief, Bureau of Entomology and Plant Quarantine 
 
UNIVERSITY OF FLORIDA^ 
 
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