- 20 - 
no place as a contaminant of foods and its household use should he strictly 
limited. Long-term feeding studies indicate that at every level of feeding 
chlordane is significantly more poisonous than comparable levels of DDT. 
From the over-all aspects chlordane is at least k times as toxic as DDT. 
SPRAY RESIDUES OF CHLORDANE 
In Colorado, Gates (l2Zl in 19^8 1 found chlordane residues on alfalfa 
after the application of one pound of the toxicant a6 an emulsion per acre 
as follows: cut 8 hours after treatment 17*9 p. p.m., 5 days 13 p. p.m., 
10 days 4.5 p. p.m., and 15 days after treatment 3*^ p. p.m. A test on 
houseflieB with an extract of the hay cut the first day indicated a chlor- 
dane residue one-half that calculated from the total chlorine content. 
When chlordane was applied to apple and peach foliage at the rate of 
1 pound (an emulsion concentrate) per 100 gallons of water, the initial 
deposit was 90.2 p.p.m. on apple foliage and 139»5 p. p.m. on peach foliage. 
After 21 days these values fell to 8.3 p.p.m. and none, respectively. 
Residue determination on alfalfa, sweet clover, red clover, and soy beans 
indicated that lindane and parathion residues are the least persistent 
followed by aldrin, chlordane, dieldrin, toxaphene, and DDT in that order. 
The waxy nature of chlordane residue makes it resistant to removal by rain. 
Chlordane residues were determined by the total chlorine method using the 
factor Cl x 1.57 = chlordane. — Decker ejt al,. (101 ). 
Chlordane in milk - A spray containing 0.5 percent of chlordane as 
a wettable powder was sprayed on milk cows four times between May 15 and 
August 29. Milk from these cows sampled from May 22 to October 27 
showed a maximum organic chlorine content of 0.8 p.p.m. and an average 
of 0.2 p.p.m. It was concluded that these amounts are so small that they 
are not regarded as definitely indicating the presence of chlordane in 
the milk. —Carter ejfc, a^. (67) . 
The danger of chlordane in milk to the public health was recognized 
by the United States Production and Marketing Administration (^2J±) which 
on May 12, 19^9 sent a notice to manufacturers, registrants, and dis- 
tributors of insecticides containing chlordane warning against the use 
of chlordane on dairy animals, or on forage or other feeds for dairy 
animals or animals being finished for slaughter, or fox use as insecti- 
cides in dairy barns. 
The American Medical Association (l6. 17 ) has expressed concern 
over the contamination of the American diet with new materials of unknown 
toxicity such as chlordane and has urged that voluntary control by the 
producers and distributors of the pesticides be instituted immediately. 
