Incidental ingestion of soil by children is an important exposure pathway for determining risk from metals introduced into soil. Total content of metal may not be related to solubility or bioavailability of metal in soil. Therefore, the use of total metal content to quantify daily chemical intake during exposure assessment is unlikely to provide an accurate assessment of risk from contaminated soil or byproduct amended soil. To overcome the difficulties and expenses associated with the conduct of animal dosing trials to assess bioavailability of metals in soils, research efforts have been directed toward the development of in vitro chemical laboratory methods. A variety of in vitro methods, that simulate the gastrointestinal environment as a means of quantifying bioavailable metals with respect to the soil ingestion pathway, have been reported. These in vitro methods have been developed to estimate metal bioaccessibility in highly contaminated soils. Incidental ingestion of soil is an important exposure pathway for determining loading of select metals from biosolids application to soil. The ability of several in vitro methods to estimate metal bioavailability in contaminated soils and their application to measure bioavailability in biosolids amended soil will be presented.