Technical Abstract: Each year the U.S. foundry industry landfills several million tons of molding sand known as green sand. Currently, there is great interest in using these waste green sands in general construction and agricultural applications. However, there is concern of organic contamination from the green sands. The objective was to determine if infrared spectroscopy could be qualitatively used to identify organic residues in the green sands. In both iron and aluminum green sands, the unique signature of organic residues were identified and aluminum green sands appeared to have higher levels of organics. Ultimately, it may be possible to use infrared spectroscopy to quantitatively determine the level of residual and potentially harmful organics in waste green sands. The ability to rapidly identify and quantify harmful organics would ensure that foundry sands are safe for use in the environment.