Providing Global Process Safety Solutions

Accident Investigation

accident investigationDr. Leggett has investigated many accidents and process upsets for national and international chemical manufacturers and pharmaceutical companies. LTC’s work supports the accident investigators and provides the needed technical expertise for the root cause analysis and post-accident risk mitigation.

We offer a unique combination of advanced chemical knowledge and wide experience in process safety engineering in support of determining the cause of the accident. Our accident investigation techniques follow well-established industry standards and result in a reliable determination of what happened and how it happened.

Determining why the accident happened requires a root-cause analysis combined with, and supported by, the forensic findings. Whenever possible we support our accident investigation work by commissioning with calorimetric hazards testing such as differential scanning, isothermal and adiabatic calorimetry. These tests are designed to mimic the process conditions immediately before and during the upset.

The following list exemplifies the range of processes and chemistries that we have investigated:

  • A fire and explosion (West Fertilizer Company, 2013) resulted in 15 fatalities and extensive damage to the facility and the surrounding neighborhood. Technical support was provided for the investigation regarding ammonium nitrate (AN) chemistry and decompositions, industry practices for storage of oxidizers and AN, and interpretation of thermal hazards test results of AN.
  • During the preparation of a sodium acetate / acetic acid buffer solution the worker received facial burns and was blinded. It was determined that sodium hydroxide (caustic soda) had been inadvertently used instead of sodium acetate. Chemical testing was performed to demonstrate the consequences of the error.
  • Ribbon-blending of a formulation containing sodium cyanurate led to its thermal decomposition. The cause was determined to be the unrecognized extent of mechanical heating of the cyanurate during blending leading to chemical decomposition.
  • Failure of an organic peroxide storage facility’s refrigeration system resulted in the loss of about 100,000 lbs of peroxides. The decomposition mechanisms of organic peroxides and the identity of the decomposition products were established. Air dispersion modeling was performed to evaluate the level of local exposure of these compounds.
  • An explosion occurred in the solvent handling area of a pharmaceutical company. Inadequate grounding and bonding of the equipment, used at the time, was the primary cause of the accident.
  • During the transfer of molten iron from a steel mill’s furnace, as part of normal operations, a hydraulic hose failed and released hydraulic fluid, at 1,500 psi, into the proximity of the furnace. The fluid vapor ignited and the subsequent explosion resulted in a fatality. Customized testing of the hydraulic fluid demonstrated that it was combustible when exposed to red hot surfaces. This was unknown at the time of accident.