H2S TOXIC RELEASE — SEWER REACTIVE HAZARD — 2 CONTRACTOR FATALITIES
Georgia-Pacific Naheola Mill Hydrogen Sulfide Poisoning
Georgia-Pacific Corporation
📍 Pennington, AL
Incident: January 16, 2002  •  CSB Report: 2004
2
Fatalities
Hydrogen Sulfide (H2S — Sodium Hydrosulfide Contacting Acidic Sewer Material)
Chemical Involved
8
CSB Recommendations
📋 Incident Summary

On January 16, 2002, two contractor workers were killed and eight others were injured when hydrogen sulfide gas was released at the Georgia-Pacific Naheola paper mill in Pennington, Alabama. Workers from an unrelated construction project were working near a tank truck unloading area when the toxic gas engulfed the area.

The gas was generated when sodium hydrosulfide — a process chemical that had spilled in the unloading area — reacted with acidic material in the nearby sewer. Hydrogen sulfide gas rose from the sewer through a fiberglass manhole cover and spread rapidly to ground level where workers were present.

The CSB found that neither Georgia-Pacific nor previous plant owners had adequately analyzed or controlled the hazards of the sewer system, including the potential for toxic gas generation from the inadvertent mixing of reactive chemicals. The two fatalities occurred among workers who had no knowledge of the chemical hazard in the area.

🔎 Key Findings
Finding 01
Sodium Hydrosulfide Contacted Acidic Sewer Material, Generating H2S
Sodium hydrosulfide spilled in the unloading area reacted with acidic material in the sewer system, generating hydrogen sulfide gas. H2S vented from the sewer through a fiberglass manhole cover.
Finding 02
Sewer System Hazard Not Analyzed
Neither Georgia-Pacific nor prior plant owners had conducted an adequate hazard analysis of the sewer system that would have identified the potential for toxic gas generation from mixing of sodium hydrosulfide with acidic materials.
Finding 03
Contractor Workers Had No Knowledge of Chemical Hazard
The two workers who died were employees of an unrelated construction contractor. They had no knowledge of sodium hydrosulfide, the sewer hazard, or the potential for H2S generation in the area.
Finding 04
H2S Can Be Immediately Dangerous at Low Concentrations
Hydrogen sulfide is acutely toxic at concentrations that can be reached rapidly when reactive chemicals mix. H2S can cause rapid incapacitation and death before workers can self-rescue.
Finding 05
Chemical Hazards Not Communicated to Contractors
The chemical hazards in and around the sodium hydrosulfide unloading area were not communicated to contractor workers operating in proximity to the area.
🔍 Root Causes
1
Reactive Hazard of Sodium Hydrosulfide with Sewer Acids Not Identified
The facility's PHA had not identified the potential for H2S generation when sodium hydrosulfide contacted acidic materials in the sewer system — a reactive hazard present in normal operations.
2
Contractor Worker Hazard Communication Absent
Contractor workers performing construction in the vicinity of the unloading area were not informed of the chemical hazards present.
3
Sewer System Not Included in Facility Hazard Review
The sewer system into which process chemicals could drain was not included in PHA as a potential reactive hazard location.
☑ CSB Recommendations
→ Georgia-Pacific / Pulp and Paper Industry
Conduct hazard analysis of sewer systems and utility infrastructure for potential toxic gas generation from process chemical mixing; communicate all chemical hazards to contractor workers in or near chemical handling areas.
→ OSHA
Clarify PSM standard requirements for contractor hazard communication to include all chemical hazards in the work area — not just PSM-covered chemicals — in the contractor safety briefing.
→ Chemical Facility Operators
Include sewer systems, floor drains, sumps, and utility lines as nodes in process hazard analysis for any facility handling chemicals that can generate toxic gases upon mixing or pH change.
→ Paper and Pulp Industry
Develop industry guidance on sewer system hazard management for facilities using sodium hydrosulfide and other chemicals that can generate H2S in the presence of acidic materials.
💡 Lessons Learned
Sewer systems and utility infrastructure are frequently overlooked in process hazard analysis because they are not part of the primary process. However, sewer systems at chemical facilities receive spills, wash-down water, and drainage from process areas — and can accumulate reactive chemical mixtures that generate toxic gases. H2S generation from sodium hydrosulfide in acidic sewers is a documented, predictable hazard that must be included in facility PHA.
Contractor workers performing unrelated work tasks at a process facility are among the most vulnerable people at that facility. They typically have no knowledge of the chemical hazards present in areas adjacent to their work, and they depend entirely on the facility's contractor safety program to inform them. When contractors are not briefed on all chemical hazards in their work area, they are working in a hidden hazard zone.
Hydrogen sulfide deserves special attention in contractor safety briefings at any facility where it can be generated, even as a secondary reaction product. H2S is immediately dangerous to life and health at concentrations that can be reached within seconds. Workers exposed to H2S at IDLH concentrations can be incapacitated before they recognize the exposure.
The two workers who died were not PSM-covered chemical process workers — they were construction workers who happened to be near a chemical hazard they knew nothing about. This illustrates why PSM's contractor safety provisions exist: to extend the facility's hazard knowledge to all workers on site.
PSI: Process Safety InformationPHA: Process Hazard AnalysisSOP: Operating ProceduresCON: ContractorsEAP: Emergency Planning
🔨 Safety Meeting Toolbox Talk
►Have you included sewer systems, floor drains, sumps, and utility lines as PHA nodes for any process handling chemicals capable of generating H2S or other toxic gases through pH change or reactive mixing?
►Does your contractor safety briefing communicate all chemical hazards in the work area — including secondary hazards from adjacent operations or utility systems — to contractors performing any type of work on your site?
►Do workers and contractors in and around chemical unloading or handling areas have access to H2S detection equipment?
►Has your facility reviewed the potential for reactive chemical mixing in your sewer or wastewater system?
Immediate Action Items
✓Add sewer systems, floor drains, and utility lines to your PHA node list for all areas handling chemicals capable of generating toxic gas through reactive mixing or pH change.
✓Review your contractor safety briefing to confirm it covers all chemical hazards in the contractor's work area — not just PSM-covered chemicals — including secondary hazards from adjacent process areas.
✓Conduct a reactive chemical mixing hazard assessment for your facility's sewer and wastewater system.
✓Verify that H2S detection and PPE requirements are established for all chemical unloading areas where H2S-generating chemicals are handled.
🔗 PSM Failures Behind This Incident

This incident traced to breakdowns across 5 PSM elements (PSI · PHA · SOP · CON · EAP). Each represents a documented gap that process safety documentation and consulting can close before a similar event occurs at your facility.

Process Safety Information (PSI)
Accurate, complete Process Safety Information is the foundation every other PSM element depends on. When PSI is missing or wrong — chemistry data, equipment specs, P&IDs — the entire hazard analysis is built on a flawed base.
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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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Operating Procedures (SOPs)
Operators cannot reliably hold safe operating limits without clear, current, enforced procedures. Deviation from acceptable operating conditions — a root cause here — is a direct consequence of SOP failure.
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Contractor Safety Management
Contractor workers must be held to the same PSM standard as employees. When contractor safety oversight fails, knowledge and compliance gaps follow contract workers onto your site.
Supporting documents in our library →
Emergency Planning & Response
When process safety barriers fail, emergency response capability determines whether the outcome is controlled or catastrophic. Gaps in emergency preparedness amplified the consequences here.
Supporting documents in our library →
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