This report describes development of a 5-cm wind tunnel designed to measure the release and retention of chemical warfare agents (CWA) from various materials under simulated environmental conditions. The wind tunnel, sized to fit within a standard chemical fume hood, provides a specified vertical velocity profile, temperature, and relative humidity (simulating the natural environment) for a sustained time period ranging from hours to weeks. The associated data acquisition instrumentation measures the time history of the vapor released during evaporation of the CWA from the material substrate whether the chemical is a sessile drop on the surface or a sorbed liquid within the substrate. The wind tunnel creates the full-scale, lower portion of the velocity profile produced by a wind-induced, atmospheric boundary layer, which passes over a full-scale drop of agent and a full-scale sample of the material substrate. This feature differentiates it from environmental type wind tunnels where scaling is required for the airflow and items being tested. The 5-cm wind tunnel has the capability to test single and multiple drops of agent. This report summarizes the design evolution, component details and operational functions. Representative data obtained in the tunnel are compared with results from other experimental sources.