Waste loads require test representations with artifacts for actual load representations have not achieved researchers' consensus for wide recognition. Disparate practices exist throughout the world for test materials, quantity and load extraction acceptance criteria from laboratory tests. Confidence in data requires application of reproducible test media as standard solid waste(s) for applications to national standards. For reproducibility, test artifacts require dimensional tolerances and specific characterized physical and chemical properties for elimination of uncertainty when specified for laboratory evaluations. Current extraction acceptance criteria permit discarding data for partial extraction indications, averaging of individual test results, or complete extraction of all test solids. Aspects of those elements in test protocols applied to laboratory data for acceptable water closet performance criteria are discussed. Results are illustrated for mixed media applications. Includes 14 references, tables, figures.