AB Specialty Silicones, LLC

Overview

On May 3, 2019, a massive explosion and fire occurred at the AB Specialty Silicones facility in Waukegan, Illinois. Four workers were killed. Nearby businesses were also damaged. The CSB final report identified a chemical reaction, hydrogen release, explosion, and fire during a batch operation involving incompatible chemicals in the EM 652 process.

Incident Snapshot

Field	Value
Facility / Company	AB Specialty Silicones, LLC
Location	Waukegan, IL
Incident Date	05/03/2019
Investigation Status	The CSB's final report was approved at a public board meeting on Friday September 24, 2021.
Accident Type	Release Investigation
Final Report Release Date	09/24/2021

What Happened

• Operators at the AB Specialty Silicones, LLC manufacturing facility in Waukegan, Illinois were performing a batch operation that involved manually adding and mixing chemicals in a tank inside the production building.
• An operator pumped an incorrect chemical into the tank, which was incompatible with another chemical that was added to the tank.
• After the incompatible chemicals were mixed, the tank contents underwent a chemical reaction. This caused a process upset in which the tank contents foamed and overflowed from the tank’s top opening.
• A fog also formed.
• The process upset produced hydrogen gas, which released inside the manufacturing facility’s production building.
• Soon after the hydrogen gas release started, it ignited, causing a massive explosion and fire.

Facility and Process Context

• AB Specialty Silicones, LLC is a U.S. manufacturer and worldwide distributor of specialty silicone chemicals, headquartered in Waukegan, Illinois.
• The operation took place inside a production building divided into the High Bay and the Low Bay. The incident occurred in the Low Bay emulsions area.
• AB Specialty had been producing EM 652 since 2013 as necessary.
• The production building’s ventilation system consisted of air movers and exhaust fans throughout the building.
• The AB Specialty production building did not have a hydrogen gas or flammable gas detection and alarm system to warn employees of a hazardous atmosphere.
• The operation involved manually adding and mixing chemicals in loosely sealed atmospheric tanks used to manufacture EM 652.
• The tanks used in the EM 652 batch process had hatch-type lids that did not seal and were often left open during the entire batch process.
• The tank in which the reaction occurred on the night of the incident was not equipped with a vent pipe.
• At least three EM 652 chemical ingredients were stored in nearly identical 55-gallon blue plastic drums.
• XL 10 and 10% KOH solution were stored in an identical drum, differentiated by a small label and bung caps.

Consequences

• Fatalities: 4 employees [Byron Biehn, Jeffrey Cummings, Daniel Nicklas, Allen Stevens]
• Injuries: Operator 3 was injured; the 2014 EM 652 explosion caused short-term hearing loss to an operator
• Environmental release: hydrogen gas released inside the manufacturing facility’s production building
• Facility damage: destroyed the facility’s production building; debris extended for several hundred feet from the building, and nearby business properties were also damaged
• Operational impact: forced the company to cease some and relocate other operations until the production building could be rebuilt

Key Findings

Immediate Causes

• Operator 1 added 10% KOH to the tank with XL 10 and TD 6/12 Blend, which reacted to produce hydrogen gas that subsequently ignited to cause the explosion.
• The combination of three chemicals—XL 10, TD 6/12 Blend, and 10% KOH—caused the chemical reaction leading to the explosion at AB Specialty on May 3, 2019.

Contributing Factors

• AB Specialty’s batch equipment and ventilation system design
• The lack of a gas detection and alarm system
• Ineffective emergency preparedness
• AB Specialty’s lack of procedures likely led to incompatible 10% KOH and XL 10 remaining in the emulsions area after their use in the first batch
• The similar appearance of the XL 10 and 10% KOH drums likely contributed to Operator 1 adding the incorrect chemical to the EM 652 batch process
• The ventilation system, which included a manually operated air mover designed to introduce outside air to the building and was positioned near the location where EM 652 was being manufactured, may have helped distribute the hydrogen in the production building and mix it with air, creating a large and explosive gas cloud
• The lack of a system to detect hydrogen gas and automatically activate an alarm contributed to personnel remaining inside the production building between the start of the hydrogen release and the time of ignition
• Without gas detectors and alarms alerting of the hazardous conditions, or effective training, the workers did not realize the necessity to evacuate

Organizational and Systemic Factors

• AB Specialty’s technical service request process did not and was not intended to assess the hazards of performing a process operation or to establish safeguards to reduce risk.
• AB Specialty did not take sufficient action to improve its hazard analysis program after finding that a lack of a comprehensive hazard analysis contributed to its 2014 drum explosion.
• AB Specialty did not perform a thorough hazard analysis of the EM 652 batch process despite known associated hazards and likelihood for the product and individual chemical component(s) to produce hydrogen.
• AB Specialty did not have a written procedure requiring employees to segregate the 10% KOH and XL 10 drums in the emulsions area or to remove leftover ingredient containers after use.
• AB Specialty relied on its operators to confirm drum content based on the label affixed to the side of the drum, which used small text for the chemical name.
• AB Specialty developed a double initial procedure practice in 2014 in an effort to prevent employees from charging the wrong materials to batch processes and as a part of AB Specialty’s compliance with the FDA’s cosmetic good manufacturing practice (“GMP”) requirement.
• AB Specialty’s double initial procedure program did not prevent a wrong material from being added to the tank.
• AB Specialty exhibited characteristics of a weak process safety culture.
• AB Specialty did not have a safety management system that addressed process safety in place at the time of the incident.
• AB Specialty was not required to implement baseline process safety management system elements to manage the safety of its processes under these regulations.

Failed Safeguards or Barrier Breakdowns

• No hazards or safeguards were documented on either TSR spreadsheet.
• AB Specialty did not have a written procedure requiring employees to segregate the 10% KOH and XL 10 drums in the emulsions area or to remove ingredient containers from the emulsions area after use.
• The tanks used in the EM 652 batch process were atmospheric and equipped with hatch-type lids that did not seal and were often left open during the entire batch process.
• The tank in which the reaction occurred on the night of the incident was not equipped with a vent pipe.
• The AB Specialty production building did not have a hydrogen gas or flammable gas detection and alarm system.
• AB Specialty did not establish a sensor maintenance program.
• AB Specialty did not implement design changes to prevent silicone contact with the sensors.
• AB Specialty did not replace the sensors by the time of the May 3, 2019, incident.
• AB Specialty did not require incompatible materials to be stored separately, did not require the removal of partial drums from the process area after use, and did not require incompatible chemicals to be visibly differentiated.
• AB Specialty did not perform an effective process hazard analysis.

Recommendations

1. Recommendation 2001-01-H-R1
   Recipient: Occupational Safety and Health Administration (OSHA)
   Status: Not specified
   Summary: Amend the Process Safety Management Standard (PSM), 29 CFR 1910.119, to achieve more comprehensive control of reactive hazards that could have catastrophic consequences.

2. Recommendation 2001-01-H-R3
   Recipient: Environmental Protection Agency (EPA)
   Status: Not specified
   Summary: Revise the Accidental Release Prevention Requirements, 40 CFR 68, to explicitly cover catastrophic reactive hazards that have the potential to seriously impact the public, including those resulting from self-reactive chemicals and combinations of chemicals and process-specific conditions. Take into account the recommendations of this report to OSHA on reactive hazard coverage. Seek congressional authority if necessary to amend the regulation.

3. Recommendation 2019-03-I-IL-R1
   Recipient: AB Specialty Silicones, LLC
   Status: Closed – Acceptable Action
   Summary: Develop hazardous gas detection and alarm programs and associated procedures based on manufacturer specifications, current codes, standards, and industry good practice guidance, for all hazardous gases that could be released near workers, including hydrogen. The program must address proper installation, calibration, inspection, maintenance, training, and routine operations. Ensure such hazardous gas detection and alarm systems are functional at all times.

4. Recommendation 2019-03-I-IL-R2
   Recipient: AB Specialty Silicones, LLC
   Status: Closed – Acceptable Action
   Summary: Establish a safety management system that addresses process safety at the AB Specialty Waukegan, Illinois facility. Include in that system elements recommended in industry guidance publications, including Center for Chemical Process Safety (CCPS) publications Guidelines for Risk Based Process Safety and Guidelines for Implementing Process Safety Management.

5. Recommendation 2019-03-I-IL-R3
   Recipient: AB Specialty Silicones, LLC
   Status: Closed – Acceptable Action
   Summary: Incorporate into operations and activities at AB Specialty the specific elements recommended in CCPS’s Essential Practices for Managing Chemical Reactivity Hazards, which are: 1. Put into place a system to manage chemical reactivity hazards 2. Collect reactivity hazard information 3. Identify chemical reactivity hazards 4. Test for chemical reactivity 5. Assess chemical reactivity risks 6. Identify and implement process controls and risk management options 7. Document chemical reactivity risks and management decisions 8. Communicate and train on chemical reactivity hazards 9. Investigate chemical reactivity incidents 10. Review, audit, manage change in, and improve hazard management practices and programs.

Key Engineering Lessons

• Reactive hazard management must include a thorough hazard analysis of the process and the specific chemical combinations involved.
• Hazardous gas detection and alarm systems are needed where hydrogen or other hazardous gases could be released near workers, and they must be functional at all times.
• Process equipment and ventilation design can influence whether a released gas accumulates and forms an explosive cloud.
• Procedural controls alone were not sufficient to prevent wrong-material charging or to manage the reactive hazard in the EM 652 process.
• Incompatible materials should be segregated and leftover containers removed from the process area after use to reduce the chance of mix-ups.
• A safety management system addressing process safety is necessary to manage reactive hazards and support effective hazard identification, controls, training, and change management.

Source Notes

• Priority 1 final report facts were used to resolve conflicts over lower-priority summaries.
• The incident involved AB Specialty Silicones, LLC in Waukegan, Illinois on May 3, 2019.
• The final report identified the event as a chemical reaction, hydrogen release, explosion, and fire.
• Recommendation status changes from later documents were used for recommendation status fields.
• Some source excerpts contained truncated recommendation text; only explicitly provided text was retained.

Reference Links

• CSB incident page

Similar Incidents

Incidents sharing the same equipment, root causes, or hazard types.

Same Equipment

• Sierra Chemical Co. High Explosives Accident — Shared equipment: Agitator · Mixer · Storage Vessel
• Environmental Enterprises Hydrogen Sulfide Release — Shared equipment: Agitator · Gas Detector · Mixer · Storage Vessel
• Bio Lab Conyers Chemical Release — Shared equipment: Pump · Storage Vessel
• Bio-Lab Lake Charles Chemical Fire and Release — Shared equipment: Pump · Storage Vessel
• Kaltech Industries Waste Mixing Explosion — Shared equipment: Pump · Storage Vessel

Same Root Cause

• ExxonMobil Baton Rouge Refinery Chemical Release and Fire — Shared failure mode: Design Deficiency · Operator Error · Procedural Failure · Training Deficiency
• BP Amoco Thermal Decomposition Incident — Shared failure mode: Design Deficiency · Operator Error · Procedural Failure · Training Deficiency
• CSB Safety Study: Remote Isolation of Process Equipment — Shared failure mode: Design Deficiency · Operator Error · Procedural Failure
• Horsehead Holding Company Fatal Explosion and Fire — Shared failure mode: Design Deficiency · Operator Error · Procedural Failure · Training Deficiency
• Key Lessons for Preventing Incidents from Flammable Chemicals in Educational Demonstrations — Shared failure mode: Design Deficiency · Operator Error · Procedural Failure · Training Deficiency

Same Hazard

• AirGas Facility Fatal Explosion — Shared hazard: Chemical Release · Explosion · Runaway Reaction
• Oil Tank Safety Study — Shared hazard: Chemical Release · Explosion · Fire
• Bayer CropScience Pesticide Waste Tank Explosion — Shared hazard: Chemical Release · Explosion · Fire · Runaway Reaction
• Kaltech Industries Waste Mixing Explosion — Shared hazard: Chemical Release · Explosion · Fire · Runaway Reaction
• BP Amoco Thermal Decomposition Incident — Shared hazard: Chemical Release · Explosion · Fire · Runaway Reaction

---

← View in Knowledge Graph