CATCH TANK OVERPRESSURIZATION — ABORTED STARTUP — 3 FATALITIES
BP Amoco Polymers Augusta Thermal Decomposition Explosion
BP Amoco Polymers, Inc.
📍 Augusta, GA
Incident: March 13, 2001  •  CSB Report: 2002
3
Fatalities
Amodel Polymer (Thermal Decomposition in Catch Tank During Aborted Startup)
Chemical Involved
6
CSB Recommendations
📋 Incident Summary

On March 13, 2001, an explosion and fire at the BP Amoco Polymers plant in Augusta, Georgia, killed three workers and injured two others. The incident occurred during an attempt to restart Amodel (polyphthalamide polymer) production after a startup had been aborted due to downstream problems. The explosion originated in a polymer catch tank.

When the startup was aborted, a large quantity of partially reacted Amodel material had been sent to the catch tank. Inside the catch tank, the material continued to react and decompose, generating gases and causing the contents to foam. The gas pressure caused a partially unbolted cover on the catch tank to blow off, breaking process tubing, and hot liquid from the tubing ignited, causing the fatal fire.

The CSB found that BP Amoco had not conducted a formal hazard analysis of the catch tank behavior during abnormal conditions. Workers in the area were not aware that the catch tank could pose an overpressurization hazard under these conditions.

🔎 Key Findings
Finding 01
Catch Tank Overpressurized During Aborted Startup
Partially reacted Amodel polymer sent to the catch tank continued to react and decompose, generating gas that overpressurized the vessel and blew off a partially unbolted cover.
Finding 02
Abnormal Condition Hazard Not Analyzed
BP Amoco had not analyzed the behavior of the catch tank during abnormal conditions such as an aborted startup. The reactive hazard of partially reacted polymer accumulating in the catch tank was not documented or addressed.
Finding 03
Workers Unaware of Catch Tank Hazard
Workers in the area were not aware that the vessel posed an overpressurization hazard during the aborted startup condition. No hazard warning or evacuation of the area occurred before the tank cover blew off.
Finding 04
Partial Unbolting of Tank Cover Created Unsafe Condition
The tank cover was partially unbolted, reducing its ability to safely contain the building pressure. The combination of partial unbolting and overpressurization resulted in the cover being explosively expelled.
Finding 05
No Reactive Hazard Documentation for Catch Tank Abnormal Operation
PSI for the Amodel production process did not document the reactive properties of partially reacted polymer intermediates under the conditions that exist in the catch tank during an aborted startup.
🔍 Root Causes
1
Reactive Hazard of Partially Reacted Polymer Not Identified in PHA
The process hazard analysis had not identified the potential for overpressurization of the catch tank by reactive gas generation from partially reacted polymer during an aborted startup.
2
Catch Tank Operating Procedures Did Not Address Aborted Startup
Aborted startup procedures did not include specific guidance on managing the catch tank when partially reacted polymer had been transferred to it — a foreseeable abnormal condition.
3
Workers Near Catch Tank During Hazardous Condition
Three workers who were killed were in the vicinity of the catch tank during the period when overpressurization was building. There was no established exclusion zone or evacuation requirement for the catch tank area during the aborted startup.
☑ CSB Recommendations
→ BP Amoco / Polymer Manufacturers
Conduct formal reactive hazard assessment of all catch tanks, reject vessels, and waste collection systems for abnormal operating conditions; document reactive properties of process intermediates in abnormal states in PSI.
→ Chemical Industry
Include abnormal operating conditions — aborted startups, upset conditions, process upsets — as explicit PHA nodes for any vessel that receives reactive process intermediates.
→ OSHA
Emphasize abnormal operation hazard analysis in PSM enforcement; require facilities to demonstrate that PHAs cover identified abnormal operating scenarios for vessels in reactive chemical or polymer service.
→ CCPS / AIChE
Update HAZOP and PHA guidance to specifically address catch tanks, reject vessels, and accumulator systems for reactive process materials.
💡 Lessons Learned
Catch tanks, reject vessels, and waste accumulation systems are often overlooked in process hazard analysis because they are downstream of the primary process and not part of normal steady-state operation. However, these vessels receive process materials under exactly the conditions — abnormal operation, upset, or startup failure — when reactive hazards are most likely to be present. PHAs must explicitly address these vessels under the full range of conditions they can receive material.
Aborted startups are one of the highest-risk transient conditions in process operations. When a startup is aborted, partially processed material must go somewhere — and the receiving vessel now contains material whose state may be unknown, reactive, or incompletely characterized. Operating procedures for aborted startups must specifically address the hazard of partially processed material in collecting vessels.
Workers should never be in the vicinity of a vessel that may be building pressure from reactive material accumulation unless they have been specifically informed of the hazard and the situation is being actively managed. When a catch tank is receiving partially reacted polymer during an aborted startup, the immediate action should be to establish an exclusion zone.
PSI for polymer and reactive chemical processes must document the reactive properties of process intermediates — not just the final product and the standard feed materials. Partially reacted intermediates can have very different hazard profiles than either the starting materials or the finished product.
PHA: Process Hazard AnalysisSOP: Operating ProceduresPSI: Process Safety InformationTRN: TrainingINC: Incident Investigation
🔨 Safety Meeting Toolbox Talk
►Does your PHA include catch tanks, reject vessels, and waste collection systems as explicit nodes, analyzed for the specific materials they receive during upsets and aborted startups?
►Do your aborted startup procedures specifically address the management of collecting vessels that have received partially processed or reactive materials? Do they establish exclusion zones?
►Does your PSI document the reactive properties of partially processed intermediates — not just feed materials and final products?
►Have workers near catch tanks or similar vessels been trained on the potential for these vessels to overpressurize during abnormal operating conditions?
Immediate Action Items
✓Add catch tanks, reject vessels, and waste accumulation systems as PHA nodes and analyze them specifically for abnormal operating conditions including aborted startups.
✓Review aborted startup procedures for all reactive chemical and polymer processes; add specific guidance for managing catch tank conditions and establishing exclusion zones when necessary.
✓Update PSI for reactive chemical and polymer processes to document reactive properties of intermediates under upset, abnormal, and aborted startup conditions.
✓Train workers near catch tanks on the potential for overpressurization during abnormal conditions; establish clear criteria for exclusion zones during aborted startup scenarios.
🔗 PSM Failures Behind This Incident

This incident traced to breakdowns across 5 PSM elements (PHA · SOP · PSI · TRN · INC). 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.
Supporting documents in our library →
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.
Supporting documents in our library →
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.
Supporting documents in our library →
Training & Operator Competency
Workers must understand process hazards — not just the steps on the page. Training records, refresher frequency, and verified competency are all OSHA PSM requirements that gaps here violated.
Supporting documents in our library →
Incident Investigation
Near-misses and prior incidents almost always signal the exact failure mode that eventually becomes fatal. When investigation is absent or superficial, those warnings go unheeded until consequences arrive.
Supporting documents in our library →
Process Safety Management Consulting & Document Library
📂
PSM Document Library
32 ready-to-deploy PSM documents covering all 14 OSHA elements — procedures, checklists, and audit templates built for facilities operating under 29 CFR 1910.119.
Browse the Library →
📊
Free PSM Health Score
Find out where your PSM program stands across all 14 OSHA elements. Our free health score surfaces your biggest gaps in under 10 minutes — no account required.
Check Your Score →
📞
Consulting Services
PHA facilitation, PSM program builds, compliance audits, and OSHA inspection support. Transparent flat-fee pricing — no retainer required to get started.
View Pricing →
📋 Explore the full incident library: All 132 CSB Case Studies →