In order to allow for variations incident to proper grading and handling in each of the foregoing grades, the following tolerances, by weight, are as follows:

(a) U.S. Extra Fancy grade:

(1) No foreign material;

(2) 0.01 percent for shell, and center wall;

(3) Zero tolerance is provided for pecan weevil larvae;

(4) 3 percent for portions of kernels which are “light amber” or darker color, or darker than any specified lighter color classification, but which are not otherwise defective; and

(5) 3 percent for portions of kernels which fail to meet the remaining requirements of the grade, including therein not more than 0.50 percent (one-half of 1 percent) for defects causing serious damage: Provided, That any unused portion of this tolerance may be applied to increase the tolerance for kernels which are “light amber” or darker color, or darker than any specified lighter color classification.

(b) U.S. Fancy grade:

(1) No foreign material;

(2) 0.01 percent for shell and center wall;

(3) No more than 2 pecan weevil larvae;

(4) 5 percent for portions of kernels which are “amber” or darker color, or darker than any specified lighter color classification, but which are not otherwise defective; and

(5) 5 percent for portions of kernels which fail to meet the remaining requirements of the grade, including therein not more than 0.50 percent (one-half of 1 percent) for defects causing serious damage, including pecan weevil larvae: Provided, That any unused portion of this tolerance may be applied to increase the tolerance for kernels which are “amber” or darker color, or darker than any specified lighter color classification.

(c) U.S. Choice grade:

(1) No foreign material;

(2) 0.01 percent for shell and center wall;

(3) No more than 5 pecan weevil larvae;

(4) 15 percent for portions of kernels which are “dark amber” or darker color, or darker than any specified lighter color classification, but which are not otherwise defective; and

(5) 8 percent for portions of kernels which fail to meet the remaining requirements of the grade, including therein not more than 1 percent for defects causing serious damage, including pecan weevil larvae.

(d) U.S. Standard grade:

(1) No foreign material;

(2) 0.01 percent for shell and center wall;

(3) 25 percent for portions of kernels which are darker than a specified color classification, but which are not otherwise defective; and

(4) 15 percent for portions of kernels which fail to meet the remaining requirements of the grade, including therein not more than 1 percent for defects causing serious damage, including pecan weevil larvae.