(1) Whenever stenciled tare weights on freight cars are employed in the sale of commodities or the assessment of freight charges, the following conditions and requirements shall apply:

(a) All newly stenciled or restenciled tare weights shall be accurately represented to the nearest one hundred pounds for inch pound units and to the nearest fifty kilograms for metric units, and the representation shall include the date of weighing.

(b) The allowable difference between actual tare weight and stenciled tare weight on freight cars in use shall be:

(I) If in inch pounds:

(A) Plus or minus three hundred pounds for cars of fifty thousand pounds or less;

(B) Plus or minus four hundred pounds for cars over fifty thousand pounds but not over sixty thousand pounds; or

(C) Plus or minus five hundred pounds for cars over sixty thousand pounds;

(II) If in metric:

(A) Plus or minus one hundred fifty kilograms for cars twenty-five thousand kilograms or less;

(B) Plus or minus two hundred kilograms for cars over twenty-five thousand kilograms but not over thirty thousand kilograms; or

(C) Plus or minus two hundred fifty kilograms for cars over thirty thousand kilograms.

(c) Tare weight determinations for verification or change of stenciled weights shall only be made on properly prepared and adequately cleaned freight cars.

(d) Tank cars, covered hopper cars, flat cars equipped with multideck racks or special superstructures, mechanical refrigerator cars, and house-type cars equipped with special lading protective devices must be reweighed and restenciled only by owners or their authorized representatives if the car bears no lightweight (empty weight) stenciling or if repairs or alterations result in a change of weight in excess of the permissible lightweight tolerance.