Site of nitric acid reactor explosion
By John L. Schumacher, MChE, PE, CFI, CFPS
How can benzoyl peroxide and sodium percarbonate cause a fire or explosion? What are the important factors to consider when evaluating the potential for self heating to ignition of alkyd resin- or linseed oil-based stain soaked rags? Why did the addition of water to a titanium fire cause a very energetic explosion? Under what circumstances can the application of solid fumigant pellets or tablets consisting of aluminum phosphide result in fires in grain bins? Why did a reactor generating concentrated nitric acid violently explode during startup after a scheduled shutdown?
These are some examples of the questions experts in chemistry and chemical engineering are often asked to address and explain to adjusters, attorneys, and ultimately a jury or judge. To some people, chemistry is like a foreign language. To others, hearing terms like enthalpy or cations or heat of formation cause them to break into an uncontrollable sweat as they are instantly reminded of their not-so-pleasant experiences with high school or college chemistry courses. It is the job of the forensic chemist or chemical engineer to interpret the language of chemistry and explain complicated concepts in easy-to-understand, plain English.
Causation theory testing is an effective tool that experts in chemistry and chemical engineering can use to get their point across. Testing can help support opinions and/or refute the opinions of opposing experts. Furthermore, testing serves as a bridge between theory and practice. Engineering calculations may be hard for the lay audience to grasp and may leave the impression of a mad scientist stuck in a laboratory. Causation theory testing, however, demonstrates in a visual manner that these sometimes difficult-to-imagine scientific concepts actually do occur in the real world.
So the next time you are confronted with an incident involving a chemical you can barely pronounce or chemical process you have never heard of, do yourself a favor and enlist the help of a chemist or chemical engineer. They will help you understand the science behind the cause, which in turn will allow you to make more informed decisions throughout the course of the investigation.
