Chemical structure and accidental explosion risk in the research laboratory

Several important explosion hazards have been briefly mentioned, including some nitro-containing substances, many of which are common, perchlorates, and peroxides as well as hazardous metal complexes such as the fulminates that are not generally illustrated. This discussion of explosion hazard with emphasis on clear illustrations of molecular structure may help guide chemical laboratory researchers, especially beginning graduate students. Those working with the hazardous materials above, or related materials, must proceed cautiously and may want to consider alternative and safer synthetic routes. There are also occurrences of physical explosions involving phase transformations or severe pressure increase that can cause equal devastation such as the shattering of glass vessels. Note that compounds are even more hazardous when multi-functionalities are present: multiple nitro, azo, and hydrazo groups; perchlorate anions; and multiple auto-hydroperoxidation sites. If energetic materials must be used, this is time for protocol review and safety personnel consultation. Do not take chances! There are standard protocols for both explosion safety and explosives sensitivity testing of new materials suspected of being explosive. This is often the work for specially trained personnel with specialized equipment and techniques such as differential scanning calorimetry and shock sensitivity in an energetic materials laboratory. The most updated MSDS on a compound or related compound should be obtained. If one must proceed with full knowledge of explosive hazards, precautions might include (i) having a spotter, (ii) working on small scale, (iii) avoiding compound drying and heating (e.g., perchlorates, peroxides), (iv) using protective gear such as a blast shield, full-face shield, thick protective apron, fire-retardant lab coat, leather gloves, and bulletproof vest, and (v) having a fire extinguisher accessible.