Fatal Reactive Chemical Explosion
Optima Belle Fatal Chemical Decomposition Reaction and Explosion
Optima Belle LLC (toll manufacturer) / Clearon Corporation (client) / Richman Chemical Inc. (broker)
📍 Belle, WV
Incident: December 8, 2020  •  CSB Report: July 6, 2023
1
Fatalities
2
Injuries
Sodium Dichloroisocyanurate Dihydrate (NaDCC / CDB-56®)
Chemical Involved
📋 Incident Summary

On December 8, 2020, a fatal explosion occurred at Optima Belle LLC in Belle, West Virginia, a toll chemical manufacturer. One worker was killed and two were injured. A shelter-in-place was issued for residents within two miles of the facility. The explosion occurred during drying of sodium dichloroisocyanurate dihydrate (NaDCC, a pool chemical), which underwent exothermic thermal decomposition in a double cone dryer operated above the material's self-accelerating decomposition temperature.

This incident exposed critical failures in the tolling/outsourced manufacturing model: Clearon Corporation owned the product but did not share critical thermal stability data with Optima Belle, the toll manufacturer. Richman Chemical Inc., an intermediary broker, also failed to facilitate proper hazard communication. Neither Optima Belle nor Clearon had conducted a process hazard analysis or reactive hazard evaluation before production began.

🔎 Key Findings
Finding 01
Reactive Hazard Data Not Shared in Tolling Arrangement
Clearon Corporation (product owner) possessed thermal stability and calorimetry data for NaDCC but did not share it with Optima Belle (toll manufacturer) — who was unaware the material could self-accelerate at elevated temperatures.
Finding 02
No Reactive Hazard Evaluation Conducted
Neither Optima Belle nor Clearon conducted a reactive hazard evaluation or PHA before NaDCC was processed in the dryer, failing to identify the thermal decomposition hazard.
Finding 03
Dryer Operated Above Self-Accelerating Decomposition Temperature
The double cone dryer was operated at temperatures exceeding NaDCC's self-accelerating decomposition temperature (SADT), triggering runaway exothermic decomposition.
Finding 04
No Tolling Process Design Safety Review
Equipment design and safeguards for the tolling process were not evaluated for adequacy before production started; the double cone dryer was not designed for reactive chemistry.
Finding 05
Inadequate Safety Data Sheet (SDS)
The SDS for CDB-56® did not clearly explain the decomposition temperature, the consequences of exceeding it, or the underlying reasons for the storage temperature limitation.
Finding 06
No PSM System at Optima Belle
The toll manufacturer had no formal PSM system — no PHA program, no MOC, no reactive hazard management, and no emergency response plan for reactive incidents.
🔍 Root Causes
1
Breakdown of Reactive Hazard Communication in Tolling
The multi-party tolling arrangement (broker → toll manufacturer) lacked a defined process for communicating critical reactive chemistry data, leaving the toll manufacturer to process a reactive substance without key safety information.
2
Absence of Pre-Production PHA
No process hazard analysis was conducted before NaDCC processing began at Optima Belle — a PHA would have identified the thermal decomposition hazard and triggered safeguard implementation.
3
Inadequate Tolling Agreement Requirements
Toll manufacturing agreements did not specify responsibilities for hazard communication, equipment suitability review, or participation in PHAs — common weaknesses in outsourced chemical manufacturing.
4
Regulatory Gap for Reactive Hazards
OSHA PSM does not specifically cover reactive hazards from process-specific conditions and self-reactive chemicals, leaving significant hazards unregulated.
☑ CSB Recommendations
→ Optima Belle
Develop and implement a written reactive hazard evaluation and management program, and a formal PSM system including PHA, MOC, and emergency planning.
→ Clearon Corporation
Develop a process knowledge management program ensuring all critical thermal stability and reactive hazard data is transmitted to toll manufacturers.
→ Richman Chemical Inc.
Establish formal tolling agreement requirements identifying roles and responsibilities for hazard communication and PHA participation.
→ OSHA
Amend PSM Standard 29 CFR 1910.119 to achieve more comprehensive control of reactive hazards, including process-specific conditions and self-reactive chemicals.
→ CCPS
Update Guidelines for Process Safety in Outsourced Manufacturing Operations to include current best practices and guidance for tolling brokers.
💡 Lessons Learned
In toll manufacturing arrangements, the product owner bears responsibility for sharing ALL critical reactive hazard data — including thermal stability, SADT, and calorimetry — with the toll manufacturer.
A process hazard analysis (PHA) must be completed before production of any reactive chemical process begins, regardless of the tolling or outsourcing structure.
Tolling agreements must explicitly define responsibilities for hazard communication, equipment suitability review, and PHA participation for all parties.
Self-reactive chemicals require specialized reactive hazard testing (DSC, ARC) to determine safe operating limits — SDS data alone is insufficient.
OSHA PSM's limited coverage of reactive hazards leaves significant community risk from reactive chemical incidents unaddressed by regulation.
PSM Element: Process Safety Culture & Continuous Improvement
🔨 Safety Meeting Toolbox Talk
▸When engaging a toll manufacturer, do we provide ALL relevant process safety information including reactive hazard testing data, calorimetry results, and SADT limits?
▸Is a pre-production PHA required and completed before starting any new tolling process involving reactive chemicals?
▸Do our tolling agreements specify roles and responsibilities for hazard communication, equipment design, PHA participation, and emergency planning?
▸Have we conducted reactive hazard testing (DSC, ARC) for all thermally sensitive materials we process or broker?
▸Does our emergency action plan address reactive chemical incidents, including shelter-in-place triggers and community notification?
Immediate Action Items
✓Develop a reactive hazard management policy covering all materials processed, manufactured, or brokered
✓Revise tolling agreements to require pre-production PHAs, hazard data sharing, and equipment suitability reviews
✓Conduct reactive hazard testing (DSC/ARC) on all thermally sensitive process materials
✓Update SDS documents to include SADT, exothermic energy data, and consequence descriptions
✓Establish emergency response plan addressing reactive chemical decomposition incidents
🔗 PSM Failures Behind This Incident

This incident traced to breakdowns across 1 PSM element (PHA). Each represents a documented gap that process safety documentation and consulting can close before a similar event occurs at your facility.

Process Hazard Analysis (PHA)
A structured PHA or HAZOP study exists to identify exactly these scenarios before they occur. When PHA is absent, superficial, or overdue for revalidation, hazards operate unseen until they kill someone.
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