All dealers and handlers engaged in the grading of grain and oilseeds shall be responsible for the proper grade determination as set forth by the official United States Standards for grain or those approved by the Commissioner of Agriculture. All persons engaged in grading of grains and oilseeds shall be certified or supervised by a person certified by the South Carolina Department of Agriculture. Training and certification of persons engaged in sampling, grading and inspection of grains and oilseeds shall be made available by the South Carolina Department of Agriculture.