Workers are exposed every day to various hazardous volatile organic/inorganic compounds (VOCs/VICs) that can affect their safety and long-term health. Gas chromatography (GC) has long been considered to be the most promising and most commonly used method to analyze various VOCs/VICs. However, bench-top GC instruments are bulky and are usually placed in centralized labs, and thus cannot be field-deployable. Meanwhile, existing portable GC and micro-GC (µGC) on the market have limited peak capacity, handle only a small, well-defined set of chemicals, and often fail when encountering complex VOCs/VICs that can be seen in a workplace. Consequently, there is an urgent need for a device capable of rapidly and sensitively analyzing a large number of VOCs/VICs while maintaining portability and being cost-effective. The goal of the proposed project is to develop a low-cost high-performance portable automated µGC device based on a novel 3- dimensional (3-D) µGC design and highly sensitive high-speed vapor sensors. It can perform rapid (<20 min), sensitive (ppt), and in-situ analysis of hundreds of workplace VOCs/VICs for worker exposure assessment. In the proposed project, a complete fully automated 3-D µGC device will be developed and built on a chip, which will include pre-concentrators, thermal injector, micro-separation columns, flow controls, and vapor detectors. Over 100 VOCs/VICs representing various workplace exposures will be used as model systems to characterize and evaluate the performance of the device. A corresponding VOC/VIC reference library will be created for those compounds. Finally, the device, in conjunction with the pre-built VOC/VIC library, will be used to quantitatively analyze VOCs/VICs in an experimental workplace environment, as well as in real-world indoor workplace and outdoor industrial or post-industrial environments. The performance will be benchmarked against conventional industrial hygiene methods. In this 3.5-year project, we will accomplish the following five specific aims: Aim 1: Design, micro-fabricate, characterize, and optimize the components for 3-D µGC devices. Aim 2: Assemble the 3-D µGC device and develop the operation/analysis algorithm. Aim 3: Integrate an automated VIC detection module. Aim 4: Characterize and optimize the 3-D µGC device, and create a VOC/VIC reference library. Aim 5: Field-test the 3-D µGC device and benchmark against conventional industrial hygiene methods. The proposed project addresses one of the NIOSH cross-sectors - “EXPOSURE ASSESSMENT” – by developing a new analytical device to better evaluate worker exposures to hazardous VOCs/VICs. The intermediate outcomes will include journal articles, citations in the literature, inventions and patents, and adoption of technologies developed in the project. The end outcomes will be a reduction in workplace hazardous exposures and related illnesses.