Napp Technologies Explosion (Lodi, NJ – 1995)
Lessons in Sensitivity to Operations and Management of Change
On April 21, 1995, at the Napp Technologies specialty chemical plant in Lodi, New Jersey, a violent explosion and fire occurred during a custom blending operation. Five workers were killed and many others were injured.
This incident is a powerful example of how lack of sensitivity to operations (ignoring repeated operating problems) and inadequate management of change (introducing a new reactive process without proper hazard review) can lead to catastrophic loss of containment.
What Happened
The plant was performing a custom blending operation for a customer. The mixture included water-reactive chemicals (aluminum powder and sodium hydrosulfite) along with other materials. Operators observed extended operating problems — the batch was unusually hot and difficult to control. Despite these warning signs, production continued. A small introduction of water or heat triggered a runaway chemical decomposition reaction, resulting in a violent explosion and fire.
Root Causes
The joint EPA/OSHA investigation identified two primary failures:
- Lack of Sensitivity to Operations: Operators and supervisors observed repeated operating problems (high temperatures, unstable batch behavior) but did not investigate or stop the process. These anomalies were treated as normal rather than critical warning signs.
- Poor Management of Change: The custom blending operation involved a new combination of reactive chemicals. This significant process change was not properly evaluated through a formal Management of Change (MOC) process, and hazards associated with the new mixture were not fully identified or mitigated.
The Sherlock Holmes Lens
A Sherlock Holmes approach would have treated the repeated operating difficulties as important clues. Instead of accepting the unstable batch as “just how it is,” the team would have asked:
- Why is this batch behaving differently than previous ones?
- What has changed in the process or materials?
- What data should we collect and what hazards might this new combination introduce?
By failing to investigate these subtle signals, the organization missed multiple opportunities to prevent the explosion.
Key Lessons Learned
- Sensitivity to Operations requires actively noticing and investigating anything unusual — even small, recurring problems.
- Management of Change must be applied rigorously to any new process, formulation, or custom blending operation.
- Repeated operating difficulties are often early warnings of a larger problem.
- Changes that affect process safety must be evaluated under all expected conditions, including abnormal operation.
Practical Recommendations
- Treat recurring operational problems as leading indicators and investigate them thoroughly.
- Apply formal MOC to any change in raw materials, formulation, or custom processes.
- Encourage a culture where operators feel safe raising concerns about unusual behavior.
- Use the “Sherlock Holmes” mindset: ask “What exactly changed?” and “Why is this happening?”
Call to Action
Review your own operations through the Sherlock Holmes lens. Are you truly paying attention to small anomalies and changes? Are all process changes — even seemingly minor custom blending operations — rigorously evaluated?
What is one practical step your team could take this quarter to improve sensitivity to operations and management of change?
References
U.S. Chemical Safety Board / EPA Joint Investigation Report: Napp Technologies Explosion
Klein, J.A., “The ChE as Sherlock Holmes: Investigating Process Incidents,”
Chemical Engineering Progress, October 2016
