d^A a U. S. DEPARTMENT OF AGRICULTURE 



fj "^ Agricultural Marketing Service 



OIL BASE FOR INSECTICIDE SPRAYS IN TOBACCO WAREHOUSES 



Prepared by 

 Stored-Product Insects Branch 

 Market Quality Research Division 



Recommendations are frequently requested for a type of oil to be used in 

 the pyrethrum and other sprays applied in tobacco warehouses. Specifications 

 for a type of oil that appears to be satisfactory, on the basis of past ex- 

 perience and observations, are therefore presented here. 



The specifications set the limits that appear to be advisable. Within 

 the indicated ranges of properties, however, certain factors should be con- 

 sidered for best performance. In the distillation range, for example, it is 

 best not to have too high a percentage of the oil fractions in the upper 

 limits . 



The heavier fractions tend to cause an objectionable greasy deposit. 

 The minimum flashpoint is set at 1^0° F. (Tag closed cup), although a product 

 in the range of l60-170 o F. would be more desirable. 



The unsulfonated residue of an oil is usually considered in connection 

 with plant injury. It is, however, also an indication of the degree of 

 refinement. It is therefore included in the specifications to aid in ob- 

 taining a product lacking potentially objectionable characteristics. For 

 example, odor is a highly important factor, and the tobacco industry is 

 extremely careful to avoid any trace of kerosene or residual oil odor. 



These specifications will be useful to tobacco companies, pest control 

 operators, and insecticide formulators in purchasing the base oil for tobacco 

 warehouse sprays. Some firms have had experience with specific oils that they 

 have already found to be suitable. Because- of the variation within products 

 that will fall within the limitations of even these specifications, it is 

 suggested that those who do not have experience in using the oils should make 

 tests on a small scale before using an unknown or new oil for application to 

 tobacco in a warehouse. This is to determine that there will be no objection- 

 able greasy deposit, residual odor, or adverse effect on the flavor of the 

 tobacco. 



Washington, D. C. March 1963 



U. & DEPT. OF AGRICULTURE 



NATION' . . 



,Vj 4h 2 81962 



CURREm St 



