EPTC (Ethyl-N,N-di-n-propylthiolcarbamate) 
PEBC (Propyl-N,N-ethyl-n-butylthiolcarbamate) 
Studies showing a direct relation between the effectiveness of EPTC 
and the clay and organic matter of the soil indicated that the material 
was strongly adsorbed. The data also suggested that soil microorganisms 
contributed significantly to the loss of EPTC toxicity when incorporated 
into soil (Fang, 1959b; Freed, 1958b; MacRae and Alexander, 1965; Sheets, 
1958). 
EPTC was hydrolyzed on standing in water. The reaction is first 
order and has an energy of activation of 7500 calories/mole (Nalewaja 
et al., 1964). 
2.8 x 1074 (20°C) 
x 
1] 
4.25 x 1074 (30°C) 
C3H7. 
af 
C3H7 
9 
N-¢-S-Co Hg +H)07(C3H7) 9NH4+CO7+Co Hs SH 
Studies with 539 
-labeled EPTC showed that this material is readily 
Sbaorhed from the soil, translocated throughout the entire plant, and 
rapidly metabolized (Fang, 1959a, 1960; Yamaguchi, 1961). No metabolites 
were identified. 
Labeled studies with PEBC showed that the metabolic breakdown in 
tomato foliage and fruits was a first-order process. The rate constant 
depended upon the tissue and the growth stage (Fang and Fallin, 1965). 
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