Honeywell Geismar HF and Chlorine Releases

📋 Incident Summary

On January 23, 2023, a heat exchanger rupture at the Honeywell Geismar chemical plant in Louisiana released hydrogen fluoride (HF) gas, chlorine gas, and other toxic process fluids. No injuries resulted from this release, but the event was one of three catastrophic HF incidents at the facility examined by the CSB -- including a June 7, 2024 hydrofluoric acid release that seriously injured one worker. HF is one of the most acutely toxic industrial chemicals: it penetrates skin rapidly, causes deep tissue destruction, and can produce fatal systemic fluoride poisoning from relatively small body surface exposures.

The CSB investigation identified a pattern of management system failures across multiple incidents at Geismar, including deficiencies in Management of Change (MOC), Mechanical Integrity (MI), Quality Assurance, Pre-Startup Safety Reviews (PSSR), Operating Procedures, and Contractor Management. Capital projects involving changes to HF-service equipment were not subjected to adequate safety review before being placed in service.

The CSB's final report, released May 27, 2025, issued four recommendations. Three target Honeywell -- requiring a comprehensive third-party PSM audit, periodic closure reporting, and a Safer Technologies and Alternatives Analysis (STAA) for the HFC-245fa unit. A fourth recommendation to the EPA calls for initiating risk prioritization of hydrogen fluoride under the Toxic Substances Control Act.

🔎 Key Findings

Finding 1

Three HF Incidents -- Systemic Pattern

The CSB investigated three separate HF incidents at Honeywell Geismar. A pattern of repeated releases at the same facility is a signal of systemic PSM failure, not isolated events.

Finding 2

Heat Exchanger Rupture Released HF and Chlorine

On January 23, 2023, a heat exchanger in HF service ruptured, releasing HF gas, chlorine, and process fluids. The rupture reflected unaddressed mechanical integrity concerns in high-hazard chemical service.

Finding 3

MOC and PSSR Deficiencies

Changes to equipment in HF service were not consistently subjected to thorough Management of Change review and Pre-Startup Safety Review before being returned to operation.

Finding 4

Contractor Safety Management Gaps

Contractor safety management at the facility did not consistently verify contractor qualifications or enforce safety procedures for work involving HF service equipment.

Finding 5

HF's Extreme Hazard Profile

Hydrogen fluoride causes deep tissue burns, penetrates skin rapidly, and can cause fatal systemic toxicity from a small exposure area. Communities near HF facilities face acute risk in any significant release.

Finding 6

Safer Technology Options Not Evaluated

Honeywell had not performed a Safer Technologies and Alternatives Analysis to evaluate whether HF use in the HFC-245fa process could be reduced, substituted, or eliminated.

🔍 Root Causes

Systemic PSM Program Deficiencies

Multiple incidents at the same facility reflect systemic PSM program failures. The pattern of HF releases was not addressed with the urgency that repeat incidents demand.

Management of Change Gaps in HF Service

Capital projects and process changes in HF service did not consistently receive adequate MOC review, allowing changes to enter service without full hazard evaluation.

Mechanical Integrity Failures

Equipment in HF service experienced failures reflecting inadequate inspection, testing, and maintenance practices consistent with PSM MI requirements.

Contractor Management Deficiencies

Contractor qualification verification and safety oversight for HF service work were insufficient to prevent HF exposure risks to contractor personnel.

HF Risk Not Evaluated at Corporate Level

No Safer Technologies and Alternatives Analysis had been conducted to assess whether HF use could be reduced or substituted with less hazardous alternatives.

☑ CSB Recommendations

→ Honeywell International

Perform a comprehensive third-party audit of the Geismar facility's process safety management systems, evaluating compliance with 40 C.F.R. 68 and 29 C.F.R. 1910.119, including MOC, MI, quality assurance, PSSR, operating procedures, and contractor management.

→ Honeywell International

Require periodic reporting updates from the Geismar site regarding the closure of all audit findings until all findings are fully closed.

→ Honeywell International

Perform a Safer Technologies and Alternatives Analysis (STAA) for the HFC-245fa unit to evaluate whether hydrogen fluoride use can be reduced, substituted, or eliminated.

→ U.S. EPA

Initiate prioritization to evaluate whether hydrogen fluoride -- including anhydrous and aqueous acid forms -- is a High-Priority Substance under the Toxic Substances Control Act. If determined to present unreasonable risk, apply requirements to eliminate or significantly mitigate the risk.

💡 Lessons Learned

⚠ A pattern of repeat incidents at the same facility is not bad luck -- it is evidence that the root cause has not been identified or corrected. Each HF incident at Honeywell Geismar should have triggered a deeper investigation into systemic PSM deficiencies.

⚠ Management of Change is the last line of defense against inadvertently introducing hazards when modifying equipment or processes. In HF service, an inadequate MOC review is not a procedural lapse -- it is a life-safety failure.

⚠ Safer Technologies and Alternatives Analysis (STAA) is a process safety best practice for facilities using acutely toxic chemicals. Facilities should periodically evaluate whether safer substitutes are technically and economically feasible.

⚠ Contractor personnel in HF service carry the same exposure risk as direct employees. Contractor safety qualification and on-site oversight are required PSM elements -- not optional.

⚠ Hydrogen fluoride's hazard profile extends beyond the facility fence line. Facilities with large HF inventories have a responsibility to evaluate whether that inventory can be reduced.

PSM Elements: MOC · MI · PSSR · SOP · CON

🔨 Safety Meeting Toolbox Talk

Topic: Hydrogen Fluoride Hazards, MOC, and Mechanical Integrity

💬Have we performed a Management of Change review for every modification to equipment in highly toxic chemical service -- even changes that seem minor or routine?

💬When was the last Pre-Startup Safety Review performed on equipment in HF, chlorine, or other acutely toxic chemical service at this facility?

💬What are the hazards of hydrogen fluoride skin contact? Do workers in HF service areas know the immediate decontamination steps and the role of calcium gluconate?

💬How are contractor qualifications verified before contractors are allowed to work on equipment in HF or other acutely toxic chemical service?

💬When did our facility last conduct a PHA that specifically evaluated catastrophic failure scenarios for heat exchangers or vessels in HF service?

💬Has our facility ever evaluated whether the use of HF or other acutely toxic chemicals could be reduced or substituted through a Safer Technologies and Alternatives Analysis?

✎ Team Action Items

✓Review MOC records for any recent changes to equipment in HF, chlorine, or highly toxic chemical service -- verify each change received a full safety review before return to service

✓Confirm that PSSR was completed and documented for the most recent equipment restart in your area -- check that all action items were closed before startup

✓Locate and review the emergency response procedure specific to an HF or chlorine release at your facility -- confirm you know the decontamination steps and alarm signals

✓Verify that all contractor personnel in your area have received site-specific safety orientation covering the toxic chemical hazards in their work area

🔗 PSM Failures Behind This Incident

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

Management of Change (MOC)

Changes to equipment, chemistry, operating limits, or procedures that bypass formal review create new hazard pathways your PHA never evaluated. MOC failures open the door to incidents like this one.

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Mechanical Integrity (MI)

Equipment must be designed, inspected, and maintained to operate safely in its intended service. Mechanical integrity failures — degraded equipment, missed inspections, deferred repairs — contributed to loss of containment here.

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Pre-Startup Safety Review (PSSR)

PSSR is the final checkpoint before hazardous chemicals are introduced into a new or modified system. When PSSR fails or is bypassed, unresolved hazards go live with the process.

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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.

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