February 2026 Safety Bulletin: Battery Safety

NEBULA SAFETY
Feb 1
5 min read

Updated: Mar 3

Issue 024: Battery Safety in Manufacturing

In This Issue

This Safety Bulletin provides an overview of battery safety and the importance of conducting a safety review to evaluate hazards and mitigate risk.

Battery Manufacturing Safety Considerations

Battery manufacturing involves handling flammable solvents, reactive materials, fine powders, corrosive electrolytes, and high stored electrical energy. Many battery technologies rely on manufacturing steps such as anode and cathode slurry preparation, coating, drying, electrolyte handling, and formation. These processes closely resemble traditional chemical operations. While not all battery manufacturing facilities are formally covered under OSHA’s Process Safety Management (PSM) standard (29 CFR 1910.119), the hazards present are consistent with those the standard was designed to address.

Industry experience shows that battery manufacturing incidents can lead to fires, explosions, toxic gas or dust releases, and significant facility damage. These events often arise from abnormal but credible conditions rather than routine operations. This highlights the importance of systematic hazard identification and evaluation.

Battery Manufacturing Process Hazards

Battery manufacturing hazards are present throughout multiple production stages. During electrode manufacturing, solvent-based anode and cathode slurries are mixed, transferred, coated, and dried, often at elevated temperatures. Subsequent assembly and formation steps introduce electrical energy and heat generation, increasing both the likelihood and severity of failure.

Failures in upstream manufacturing steps may not immediately manifest. However, they can propagate into downstream operations. The presence of electrical energy, confinement, and dense cell arrangements can significantly escalate consequences.

Anode and Cathode Slurry Manufacturing Hazards

Anode and cathode slurries typically consist of active material powders, binders, conductive additives, and liquid solvents. Slurry preparation systems include agitated vessels, pumps, transfer piping, coating equipment, drying ovens, and exhaust ventilation systems. These operations introduce several credible hazards that are well suited for evaluation using Process Hazard Analysis (PHA) techniques.

Potential PHA-identified hazards include:

Accumulation of flammable or toxic solvent vapors due to ventilation or exhaust failure
Static discharge during slurry transfer or coating operations
Ignition of solvent vapors in coating or drying equipment
Combustible dust hazards from dried electrode materials
Loss of temperature control in drying ovens
Loss of containment of toxic additive solids

Formation, Testing, and Electrical Hazards

Formation and testing steps introduce electrical energy to newly assembled cells. In certain battery technologies, including lithium-ion systems, abnormal charging or testing conditions can result in overheating, gas generation, internal short circuits, or cell failure.

Potential PHA-identified hazards include:

Cell overheating and initiation of thermal runaway
Propagation of failure to adjacent cells or equipment
Generation of flammable or toxic gases under abnormal conditions
Inadequate ventilation in formation or testing areas
Electrical faults, unintended current paths, or equipment failures

Multiple industry incidents have involved fires during formation or early testing. A single cell failure can escalate rapidly due to close spacing, insufficient thermal isolation, or delayed detection.

Thermal Runaway and Escalation Potential

Thermal runaway represents one of the most severe hazards in battery manufacturing, particularly for high-energy battery chemistries. Once initiated, thermal runaway can produce intense heat, flammable gases, and toxic decomposition products. This can potentially overwhelm ventilation, fire detection, and suppression systems.

Recent manufacturing incidents, including large-loss fires at battery production facilities, have demonstrated how rapidly thermal events can escalate. This occurs when cells are densely packed or when failures propagate between process stages.

PHAs are particularly effective at identifying:

Credible initiating events for thermal runaway
Escalation pathways between cells, racks, and process equipment
Dependencies on ventilation, cooling, power, and control systems
Limitations of passive and active safeguards during abnormal conditions

Manufacturing Quality and Latent Defect Risks

Many battery manufacturing incidents can be traced back to latent defects introduced earlier in the process. Contamination, inconsistent bonding or welding, mechanical damage, or process variability may not be detected immediately. However, these issues can contribute to failure during formation or later stages.

Potential PHA-identified risks include:

Introduction of defective cells into high-energy processes
Limited inspection capability for critical defects
Single-point failures in quality or control systems
Poor traceability of materials or process conditions

Evaluating how quality-related failures interact with thermal and electrical hazards is a key strength of structured PHA methodologies.

Applicable Codes, Standards, and Guidance

Occupational Safety and Process Safety

OSHA 29 CFR 1910.119 – Process Safety Management of Highly Hazardous Chemicals
OSHA 29 CFR 1910 Subpart H – Hazardous Materials
OSHA 29 CFR 1910 Subpart S – Electrical Safety
OSHA 29 CFR 1910 Subpart Z – Toxic and Hazardous Substances

Fire and Explosion Protection

NFPA 30 – Flammable and Combustible Liquids Code
NFPA 68 – Explosion Protection by Deflagration Venting
NFPA 69 – Explosion Prevention Systems

Electrical and Equipment Safety

NFPA 70 (NEC) – National Electrical Code
UL 1642 – Lithium Cell Safety
UL 1973 – Battery Systems Safety
UL 9540 / UL 9540A – Battery System Safety and Thermal Runaway Testing

Ventilation and Industrial Hygiene

ACGIH Industrial Ventilation Manual

Process Safety Guidance

CCPS Guidelines for Hazard Evaluation Procedures
CCPS Guidelines for Risk-Based Process Safety

While these standards provide important requirements and guidance, they do not replace the need for facility-specific hazard evaluation.

The Role of PHAs in Battery Manufacturing

While PHAs are not explicitly required by regulation for many battery manufacturing operations, they provide a structured framework for identifying and evaluating high-consequence hazards. These hazards may not be fully addressed by prescriptive codes or equipment standards alone.

PHAs add value by:

Evaluating abnormal but foreseeable operating conditions and associated hazards
Identifying interactions between chemical, thermal, mechanical, and electrical systems
Assessing loss-of-utility scenarios such as ventilation, cooling, or power failures
Identifying escalation pathways and safeguard dependencies
Supporting defensible, risk-based decision making
Demonstrating alignment with recognized and generally accepted good engineering practices (RAGAGEP)

Why PHAs Should Be Strongly Considered

The absence of a legal requirement does not eliminate risk. Battery manufacturing has demonstrated the potential for high-severity incidents driven by abnormal but foreseeable conditions. These include thermal runaway, fire propagation, and toxic gas release.

For battery manufacturing facilities—particularly those involving solvent-based slurry systems, coating and drying operations, and high-energy formation steps—PHAs should be strongly considered. This is part of a comprehensive approach to process safety. Applying PHA rigor helps organizations proactively identify vulnerabilities, evaluate safeguards, and reduce the likelihood of fires, explosions, and production-impacting events.

References:

Nebula Safety and Environmental is experienced in facilitating and supporting PHAs. Please reach out to the Nebula Safety and Environmental Team at NebulaSafety.com for additional information.

At Nebula Safety & Environmental, we believe safety is more than compliance — it is a commitment to protecting people, strengthening operations, and building responsible organizations. Guided by integrity, accountability, client commitment, leadership, and teamwork, we partner with companies to proactively identify risk, strengthen safeguards, and implement practical solutions that work in the real world.

Our comprehensive safety and environmental consulting services are designed to safeguard personnel, protect assets, and promote environmental responsibility across every stage of your operations. From hazard evaluations and process safety support to regulatory guidance and risk-based decision-making, Nebula delivers expertise you can trust.

If you’re ready to strengthen your safety culture and build a more resilient operation, connect with the Nebula Safety & Environmental team today.