The growing and immediate threat of biol. and chem. weapons has placed urgency on the development of chem. and biol. warfare agent (CWA/BWA) screening devices.Specifically, the ability to detect CWA/BWA prior to deployment is paramount to mitigating the threat without exposing individuals to its effects.SPARTA, Inc. and NIST are currently investigating the feasibility of using far-IR radiation, or terahertz (THz, 1 THz = 1012 Hz) radiation, to non-invasively detect biol. and chem. agents, explosives and drugs/narcotics inside sealed containers.Small-to-medium sized mols. (3-100 atoms) in gas, liquid and solid phases consistently exhibit identifiable spectral features in the far-IR portion of the spectrum.Many compounds associated with weapons of mass destruction are made up of mols. of this size.The THz portion of the spectrum lies between visible light and radio waves, allowing for partial transmission of 0.3-10.0 THz (30-1000 μm, 10-330 cm-1) light through most common materials.Therefore, transmission measurements of THz light can potentially be used to non-invasively detect the presence of CWA/BWA, explosives and drugs in the pathway of a THz radiation beam.