Foliage safe levels

This paper establishes toxicologically-safe levels for total residues of parathion, azinphosmethyl, methidathion and their oxons on tree foliage and reports these levels in terms of absorbance units as determined by the rapid field method. Safe levels for a new insecticide, chlorthiophos, are also proposed based on preliminary residue data. Chemical structures of the four insecticides mentioned above are shown in figures 1, 2, 3 and 6. 

Safe Levels for Parathion, Azinphosmethyl, Methidathion and Their Oxons on Tree Foliage... 

Table II gives a procedure for establishing safe levels for total dislodgeable thion + oxon residues on tree foliage.

Table I. Establishment of Safe Levels on Tree Foliage (in ug/cm ) Using the Results of Dermal Dose-ChE Response Curves and Field Reentry Studies according to Knaak et al. (3)...

Insecticide or Alteration Product— Slopes ED50 2 in ug/cm of Total Body Surface Relative.. Toxicity - c / Safe Level on— Foliage in ug/cm... 

The safe levels established for parathion + paraoxon, azinphosmethyl + azinphosmethyl oxon and methidathion + methi-dation oxon on foliage have absorbance values determined by the rapid field method (4 ) equal to those given in Table III. Absorbance values greater than those listed in Table III signal an unsafe working condition. Field testing can also be conducted by standard gas chromatographic analysis of the leaf disk samples by state-approved laboratories. 

Table III. Absorbance Values for Safe Levels of Total OP Residues on Foliage...

Knaak, J.B., P. Schlocker, C.R. Ackerman and J.N. Seiber (1980). Re-entry research establishment of safe levels on foliage. Bull Environ. Toxicol, 24, 796-804. 

Testing Foliage for Safe Insecticide Residue Levels Using the Rapid Field Method... 

Knaak, J. B. Schlocker, P. Ackerman, C. R. Seiber, J. N. Reentry Research Establishment of safe pesticide levels on foliage. Bull. Environm. Contam. Toxicol., 1980, 24, 796. 

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