Reactive Chemicals

To safely handle and use chemicals (or products that incorporate chemicals), users must understand the hazards associated with these materials. In particular, certain chemicals can spontaneously decompose or explode, especially at elevated temperature or pressure. Other chemicals may react violently when mixed with incompatible materials. These reactions may result in death and injury to people, damage to physical property, and severe effects to the environment. All chemical reactions involve energy changes. The activation energy is the energy necessary to start the reaction, and the heat of reaction is the energy released (or absorbed) during the reaction. An exothermic chemical reaction releases energy, while an endothermic reaction absorbs energy. If a chemical reaction releases energy, either very rapidly or in very large quantities, and the process cannot absorb the excess energy, it has the potential to damage the containment structure or surroundings. Accordingly, mitigation strategies for reactive hazards are typically focused on controlling the rate and extent of energy release. Because most reactions speed up at higher temperature and pressure, a typical strategy to prevent a chemical runaway reaction requires active cooling or venting. While classic thermodynamics allows a top-level view of whether a specific reaction can or cannot occur under given conditions of temperature or pressure, the rate at which the reaction will actually occur has to be determined by incorporating experimental or numerical tools from a chemical kinetics repertoire. By balancing the rate of energy release against the rate that the energy is absorbed (or otherwise used up), it is possible to predict whether a specific chemical combination will cause a runaway chemical reaction.

Exponent engineers and scientists have significant experience in evaluating reactive chemical hazards for a wide variety of industrial, commercial, and residential applications. For more than 40 years, we have investigated thousands of incidents, ranging from large explosions or detonations caused by a runaway chemical reaction, to small fires caused by the self heating of oil-soaked rags stored in a manner that allowed trapped heat to accumulate. Results of our research and investigations are frequently published or presented in peer-reviewed journals and technical symposia, including the Loss Prevention Symposium sponsored by the American Institute of Chemical Engineers (AIChE) and the Mary Kay O’Conner Process Safety Center at the Texas A&M University. Exponent also conducts audits of chemical and industrial processes, and offers design review and chemical analysis of consumer products and equipment to determine compliance with applicable United Nations (UN), U.S. Department of Transportation (DOT), and other federal and state regulations. We also assist our clients in developing appropriate risk management, mitigation, and hazard communication strategies.