There is no real-time non-invasive in-situ benzene monitors available in the market with sufficient sensitivity, selectivity and speed that would comply with the new rules and regulations introduced in the USA (Federal register, Vol 80 (230), Part II, Environmental Protection Agency, “Petroleum Refinery Sector Risk and Technology Review and New Source Performance Standards; Final Rule”, December 1, 2015) for petroleum industry and soon to be adopted worldwide. This product is a standalone benzene monitor that has the capability to store data on its hard drive as well as communicate to a cloud (based on user preferences) thereby allowing a network of monitors that can be distributed along the fence lines of the target industrial facilities. The innovation involved in the product is not only in the operational side, but also in the technological side. The main principle of the instrument is the UV cavity-enhanced absorption spectroscopy, which is a proven technology for atmospheric trace gas sensing. By incorporating off-axis optical cavity technique in the instrument the signal stability and accuracy is greatly improved. This is a translation of latest optical instrumentation technologies applied to benzene monitoring. Standalone capability also requires development of advanced electronics and communication protocol and the same is incorporated in the instrument.