As green hydrogen becomes central to global decarbonization strategies, its deployment in industrial environments raises important engineering and safety questions. Facilities that handle hydrogen at scale—particularly those operating under hazardous conditions—must adopt stricter monitoring and control strategies to ensure operational safety. Central to this effort are advanced gas analysis tools, particularly the oxygen analyzer and hydrogen analyzer, which help manage the invisible risks associated with hydrogen’s unique properties.
Understanding the Risk Landscape
Hydrogen is often promoted as a clean and efficient energy carrier, but it also presents specific risks. With an ignition energy as low as 0.02 millijoules and a flammable range extending from 4% to 75% in air, hydrogen is significantly more volatile than many other industrial gases. Its low density and small molecular size make it prone to leakage through fittings and seals that would be considered secure for other substances.
In enclosed or congested industrial spaces, undetected hydrogen releases may form explosive mixtures—especially if ignition sources are present. These conditions necessitate comprehensive monitoring strategies, particularly in facilities that operate at elevated pressures, such as water electrolyzers generating green hydrogen at up to 200 bar.
The Role of Gas Analyzers in Risk Mitigation
To detect and respond to potentially hazardous conditions, industrial sites rely on real-time gas monitoring systems. A hydrogen analyzer is used to quantify hydrogen concentrations in process streams or ambient environments, detecting abnormal releases or deviations from expected process conditions. A oxygen analyzer, by contrast, plays a critical role in identifying the presence of oxygen—either as a byproduct of electrolysis or as an impurity that could increase flammability risks in hydrogen systems.
In high-pressure environments, in-situ analyzers are often preferred over extractive sampling systems. This is due to the inherent dangers in transporting flammable gases through long sample lines and the need for fast response times. In-situ analyzers provide immediate, localized readings and reduce the risk associated with leaks in sampling infrastructure.
Gaps in Safety Practices and Infrastructure
While safety standards for hydrogen are well established in the oil and gas industry—through frameworks such as ATEX, IEC 60079, and NEC 500/505—these are not always rigorously applied in new green hydrogen projects. Developers without experience in hazardous gas handling may underestimate the importance of area classification, gas group categorization, and zone-specific equipment.
Moreover, supporting infrastructure commonly found in conventional hydrocarbon processing—such as flares, controlled venting, or nitrogen purging systems—is often missing from modular or containerized green hydrogen units. The absence of these features can increase dependence on manual intervention, raising the risk of error during commissioning, maintenance, or emergency scenarios.
Functional Safety and the Justification for SIL-2
To ensure that control systems respond appropriately to detected hazards, many industrial operations implement functional safety systems in line with the IEC 61511 standard. Safety Integrity Levels (SIL) define how reliably a safety system must perform under demand. For hydrogen systems, SIL-2is generally considered appropriate for critical safety functions such as:
- Automatic shutdown upon hydrogen leak detection
- Interlocks to prevent dangerous oxygen levels
- Sequencing of pressure relief and venting systems
- Fire and gas detection-based emergency shutdowns
The application of SIL-2 requires redundancy, diagnostic coverage, and proof testing, alongside instrumentation with demonstrated reliability. A well-calibrated hydrogen analyzer or oxygen analyzeroften serves as the initiating element in these safety loops, making their performance and reliability central to the safety strategy.
Integrating Safety Into System Design
To reduce risk in industrial hydrogen operations, several best practices are widely recommended:
- Use in-situ gas analyzers for continuous monitoring of hydrogen and oxygen
- Minimize mechanical fittings by preferring welded connections
- Perform formal hazardous area classification studies based on realistic leak and dispersion scenarios
- Design for controlled venting or flaring during overpressure events
- Include purge and inerting systems to safely manage startup and shutdown phases
- Implement SIL-rated safety instrumented functions for process-critical operations
- Train personnel specifically in hydrogen-related hazards and response protocols
Conclusion
Green hydrogen offers a promising route to decarbonization, but its integration into flammable industrial environments must be approached with caution. The physical properties of hydrogen demand specialized safety systems and operational discipline. Instruments like the oxygen analyzer and hydrogen analyzer are essential tools in this context—not only for process optimization but also for ensuring workplace safety and regulatory compliance. One company addressing these gaps is Modcon Systems, which integrates in-situ hydrogen and oxygen analyzers with AI-driven optimization frameworks, eliminating the need for extraction and aligning with SIL-2 requirements for high-pressure environments.
Rather than viewing hydrogen deployment as a straightforward scaling of electrolysis, stakeholders must acknowledge and address the complexities of hazardous area classification, real-time gas monitoring, and functional safety integration. Doing so will support both the growth of green hydrogen infrastructure and the safety of the environments in which it operates.
References
- IEC 61511: Functional Safety – Safety Instrumented Systems for the Process Industry Sector. International Electrotechnical Commission (2016). https://webstore.iec.ch/publication/7033
- ISO/TR 15916: Basic Considerations for the Safety of Hydrogen Systems. International Organization for Standardization (2015). https://www.iso.org/standard/41176.html
- Hydrogen Safety Best Practices Manual. Center for Hydrogen Safety (AIChE), Pacific Northwest National Laboratory. https://h2tools.org/bestpractices
- Fuel Cells and Hydrogen Joint Undertaking. Hydrogen Roadmap Europe – A Sustainable Pathway for the European Energy Transition (2019). https://www.clean-hydrogen.europa.eu/media/419/download
- Modcon Systems. Real-Time Monitoring of Hydrogen and Oxygen in Electrolyzers. https://www.modcon-systems.com/green-hydrogen-production/
- Modcon Analyzers. In-Situ Gas Analyzers for Process Safety. https://modcon-analyzers.com/analyzers_cat/gas-analyzers/
