Introduction
When Moss Landing experienced a BESS fire in January 2025, a portion of the facility burned for several hours and released smoke and ash into nearby communities. Local agencies later documented reports of respiratory irritation and animal health issues linked to the incident.
In the days that followed, environmental researchers identified a more serious outcome. The fire produced toxic metal fallout, depositing an estimated 55,000 pounds of nickel, manganese, and cobalt across surrounding wetlands. This expanded the industry’s understanding of BESS risk. Thermal runaway and fire propagation are well studied, but the environmental deposition of heavy metals introduced an entirely new dimension of impact for grid scale lithium-ion systems.
These metals stick to soil and water surfaces, persist through rainfall and tidal movement, and can move into wildlife through the plants and animals that live in the area. Moss Landing demonstrated that battery fires are not only thermal events. They are environmental disruptions with consequences that stretch far beyond the burn period.
This reality highlights the need for technologies that prevent combustion and neutralize hazardous byproducts before they escape containment. EticaAG’s LiquidShield immersion cooling technology and HazGuard gas neutralization system were developed to meet these challenges by stabilizing cells, suppressing runaway and significantly limiting environmental release as storage deployments continue to scale.
Environmental Findings from the Moss Landing Fire
Toxic Metals Detected Across Wetlands
Researchers from Moss Landing Marine Laboratories conducted rapid sampling across Elkhorn Slough immediately following the incident. Because extensive pre-fire baseline data existed, shifts in soil chemistry were quickly identified.
Key findings included:
- Elevated levels of nickel, manganese, and cobalt across marsh surfaces
- A thin but widespread contaminated surface layer in the upper millimeters of sediment
- Patchy deposition patterns driven by smoke plume direction, wind, and terrain
- An estimated 25 metric tons of heavy metals deposited across 1.2 km² of wetlands
- Evidence suggesting the sampled layer represented only about 2% of the total fallout
This event became the first documented case of a utility scale lithium-ion battery fire producing measurable toxic metal contamination across a natural ecosystem.
How Metals Moved Through the Wetland System
Once deposited, the metals did not remain fixed in place.
Environmental transport included:
- Rain events pushing contaminants deeper into soils
- Tidal exchange redistributing metals across Elkhorn Slough
- Runoff moving particulates toward estuarine channels and potentially Monterey Bay
These mechanisms created a dynamic contamination footprint that continues to shift with weather and hydrology.
Ecological Exposure Pathways
Researchers identified several biological exposure routes with long-term implications.
Primary concerns included:
- Invertebrates ingesting contaminated surface sediments
- Metals accumulating in fish, affecting organ and reproductive health
- Shorebirds and marine mammals exposed through contaminated prey
- Long term biomagnification due to metal persistence in sediment
Elkhorn Slough is one of California’s most ecologically sensitive wetlands. Even modest increases in heavy metal concentration can disrupt feeding behavior, reproduction, and species health.
Why These Findings Matter
The Moss Landing fallout demonstrated that:
- Contamination extended far beyond the BESS footprint
- Metals continue to move through the environment long after the fire is extinguished
- Wildlife faces exposure across multiple levels of the food web
The fire ended relatively quickly, but the environmental effects will last far longer.
Why Metal Fallout from BESS Fires Is So Dangerous
Battery Cathode Materials Become Airborne Toxins
Nickel, manganese, and cobalt do not remain stable during thermal runaway. Once temperatures rise high enough, these materials fracture and attach to fine smoke particulates. The particulates travel broadly through smoke plumes and settle across soil and water. Heavy metals persist for years, creating long term ecological exposure.
Thermal runaway in large, energy dense modules generates ideal conditions for this dispersal, which makes prevention a top priority.
Fire Suppression Challenges in Large-Scale Packs
Large BESS systems face significant suppression challenges due to their size and energy density. Traditional cooling methods, whether air based or liquid based, can struggle to maintain stable temperatures across densely packed cells. When certain areas begin to warm faster than others, localized hotspots can form, and these hotspots increase the likelihood that a single cell will enter thermal runaway. Once that happens, neighboring cells can heat rapidly, and the reaction can escalate across an entire module.
When temperatures rise beyond the limits of conventional suppression tools, water mist, inert gas, and aerosol agents often lose effectiveness. These methods cannot always reach the internal reaction point or remove heat fast enough to stop the progression. Cell level thermal management becomes essential because suppression systems alone cannot prevent runaway once it has already advanced inside a battery module.
The Regulatory Gap
Current codes focus on explosion prevention, emergency access, and slowing thermal propagation. What they do not address is environmental fallout created when cathode materials disperse during combustion. There is no requirement to assess or mitigate heavy metal deposition in most permitting frameworks.
Moss Landing revealed the need for stronger environmental planning in BESS deployments, especially near wetlands, waterways, and agricultural lands.
How Gas Neutralization Protects Air and Soil During Fault Events
Even with strong preventive measures, facilities must be prepared for rare high severity events. This is where gas neutralization becomes essential.
The Problem: Toxic Gas Plumes from Battery Fires
Battery combustion produces:
- Hydrofluoric acid (HF)
- Volatile organic compounds (VOC)
- Fine metal bearing particulates
These gases spread widely through smoke plumes and contribute directly to environmental contamination. Public concern often centers more on these toxins than the fire itself, since off-gases can impact both human health and ecosystems quickly.
Metal particulates in smoke are also a primary mechanism by which heavy metals settle into soil and wetlands. Reducing toxic off-gassing directly reduces metal fallout.
HazGuard: Neutralizing Toxic Gases Before They Exit the Enclosure
HazGuard provides a direct solution by neutralizing harmful gases before they can escape the enclosure.
HazGuard captures and converts off-gases through a multi-stage physicochemical process into non-toxic, non-flammable inert gases.
This includes:
- Neutralization of HF
- Breakdown of VOCs
- Conversion of reactive gases into stable inert compounds
- Filtration that traps metal-bearing particulates
By neutralizing harmful gases before they leave the enclosure, HazGuard eliminates the pollutants that can travel into surrounding communities and natural areas. This prevents the kind of toxic plume conditions that allowed heavy metals to spread so widely during the Moss Landing fire.
HazGuard directly addresses the risk that communities fear most: the impact that toxic gas release can have on people and the environment.
Environmental Protection Benefits
HazGuard provides clear environmental advantages:
- Reduced deposition of metal contaminants into wetlands and soil
- Lower airborne concentrations of toxic gases
- Reduced risk to communities and first responders
- Smaller remediation footprint after an event
HazGuard is especially valuable for projects near coastlines, waterways, agricultural regions, or population centers.
How Immersion Cooling Reduces the Risk of Toxic Metal Release
Immersion cooling addresses another core driver of metal fallout: the extreme temperatures that cause cathode materials to break down and aerosolize. Stabilizing temperature at the cell level is one of the strongest ways to prevent runaway altogether.
Thermal Runaway Prevention at the Cell Level
The LiquidShield immersion cooling technology surrounds every cell with a Shell certified high-performance dielectric fluid. This fluid rapidly absorbs and distributes heat, creating a stable thermal environment. Cells operate within tight temperature bands, reducing mechanical stress, and lowering the probability of runaway.
Stable temperatures also slow degradation, meaning longer life, better performance, and improved reliability over the system’s full-service cycle.
Halting Propagation Before It Starts
If a defect causes a cell to fail, the immersion fluid removes heat faster than thermal runaway can spread. Neighboring cells stay cool and stable, halting propagation before it can become a rack level event.
Maintaining lower peak temperatures also reduces the breakdown of cathode materials. If temperatures never reach combustion thresholds, metals like nickel, manganese, and cobalt are far less likely to aerosolize.
Fire Suppression Built into the Cooling Medium
The immersion fluid also acts as a passive suppressant. By surrounding each cell, the fluid limits oxygen exposure and slows chemical reaction rates during abnormal events. This results in far fewer combustion byproducts and a cleaner, more controlled failure response.
Beyond Prevention: What Moss Landing Shows About Future BESS Design
Why Large-Scale Projects Need Upgraded Safety Architectures
As BESS installations scale into multi GWh facilities, both thermal and chemical risks scale as well. Environmental modeling must now include potential metal fallout, along with fire spread.
Moss Landing proved these risks are real.
The Case for Immersion Cooling as a Baseline Technology
Immersion cooling transforms system behavior during faults. Temperatures stay contained, and propagation slows. The system also maintains stability even in severe anomalies.
Compared to air and liquid plate cooled racks, immersion cooling provides stronger thermal control and much faster heat removal.
Integrating Gas Neutralization as a Regulatory Expectation
HazGuard aligns with the direction of future safety and environmental standards. Regulators, insurers, and utilities are increasingly focused on mitigating toxic emissions during fault events.
HazGuard provides this capability today, helping developers demonstrate environmental stewardship and risk reduction.
Implications for Utilities, Policymakers and Developers
The Moss Landing incident is likely to influence permitting and risk assessments moving forward. Environmental impact reviews may begin to incorporate metal deposition modeling and off-gas dispersion analysis more regularly, especially for projects near sensitive habitats or population centers. Insurers may also take a closer look at how different BESS configurations manage thermal and chemical risks.
Lifecycle environmental safety is expected to play a growing role in how large BESS projects are evaluated. Stakeholders may place greater emphasis on solutions that limit both thermal escalation and chemical release during fault events.
EticaAG’s integrated architecture, which combines HazGuard and LiquidShield, offers a pathway to address both chemical and thermal hazards in a unified safety framework. This approach can support a safer, cleaner, and more resilient direction for utility-scale energy storage.
Conclusion
The Moss Landing fire provided a significant lesson for the entire industry. A single event produced widespread environmental contamination and heightened public concern. Heavy metal fallout was scientifically confirmed across wetlands, and ecological risks are still being evaluated.
Immersion cooling and gas neutralization represent proven pathways to prevent fires, limit toxic emissions, and protect ecosystems from unintended fallout. These systems improve performance and safety simultaneously, setting a higher standard for resilient BESS design.
As energy storage continues to grow, utilities, developers, and policymakers must prioritize technologies that eliminate runaway, neutralize gases, and prevent environmental release. LiquidShield and HazGuard deliver these capabilities today, creating a safer path for the next generation of grid-scale energy storage.
