INSECTICIDES AND REPELLENTS 87 



reported to damage tissue. A single application of 1 -percent spray 

 has caused toxic effects in calves. On cattle 2-percent sprays pro- 

 duced toxic effects after 2 or 3 treatments 2 weeks apart. DDT and 

 toxaphene applied at the same time, concentration, and interval 

 caused no observable toxic effects after 10 treatments. 



Chlordane is not stored in fat of beef cattle so readily as is DDT, 

 and it is eliminated more quickly. 



Chlordane is volatile, and the vapors may create a hazard when 

 large amounts are applied in buildings. The toxic effects of such 

 vapors to man and animals have not been we]] established. 



Special Precautions in Using Chlordane 



Do not apply on man. 



Do not use for residual treatment of large areas of walls and ceilings in 

 homes and industrial establishments. Limit its use to spot treatments in 

 places where such pests as cockroaches, ants, and silverfish hide and run. 



Do not apply in dairy barns or milk rooms. 



To avoid possible damage to fish and wildlife, exercise the same pre- 

 cautions listed for DDT (see p. 84). 



TOXAPHENE 



The acute oral toxicity of toxaphene is much higher than that of 

 DDT, chlordane, or lindane. The median lethal oral dose for labora- 

 tory animals is about 69 mg. per kilogram of body weight. The 

 chronic oral toxicity is lower than that of DDT or chlordane. 



When applied to calves toxaphene is much more toxic acutely 

 than DDT, but less so than lindane. Calves are poisoned occasionally 

 when treated with 1 -percent sprays, which represents about the same 

 acute dermal toxicity as for chlordane. However, in contrast to 

 chlordane repeated treatment of calves every 2 weeks or at even 

 shorter intervals caused no accumulative toxic effects. When con- 

 sumed orally toxaphene is not readily stored in body fat and is not. 

 readily excreted in milk of dairy cattle. When storage does occur at 

 rather high levels of intake, the residues disappear from the body 

 much more quickly than those of DDT. 



Toxaphene is highly toxic to fish. 



Special Precautions in Using Toxaphene 



Do not apply on man. 

 Do not use inside homes. 



Do not use for controlling mosquito larvae if fish are present. 

 For chigger or tick control near streams or ponds apply carefully to avoid 

 accidental contamination of the water. 



DIELDRIN 



The major limiting factor in the use of dieldrin is its high acute 

 and chronic toxicity to man and animals. Its acute oral toxicity to 

 laboratory animals was found to be about 87 mg. per kilogram of 

 body weight on the basis of the median lethal dose. 



On the same basis the acute dermal toxicity of dieldrin in oil 

 averages less than 150 mg. per kilogram of body weight. On repeated 



