Whether occurring accidentally or through acts of terrorism, catastrophic chemical releases must be identified early in order to mitigate their consequences. Continuous sensor monitoring can detect catastrophic chemical releases early enough to curb extreme amounts of damage. In several notable instances, such monitors have not been used appropriately, or have fallen short of what they should have been capable of delivering. This book provides the technical background and guidance needed to get the most from this emerging technique and details the essentials of preparing any workplace from falling victim to a gas-leak catastrophe.