Electrolysis plants, particularly those producing hydrogen through alkaline, proton exchange membrane (PEM), or solid oxide electrolyzer cell (SOEC) technologies, must adhere to stringent international safety protocols. These standards ensure safe operation by addressing hazards unique to electrolysis, including gas leaks, electrical risks, and thermal management. Key standards are established by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC), which provide guidelines for design, operation, and maintenance.

ISO 22734 outlines safety requirements for hydrogen generators using water electrolysis. It covers the entire system, including gas production, storage, and handling. The standard mandates leak detection systems, pressure relief mechanisms, and automatic shutdown procedures in case of malfunctions. Electrolysis plants must incorporate fail-safe designs to prevent gas accumulation, with particular attention to hydrogen’s wide flammability range (4–75% in air). Ventilation systems must ensure hydrogen concentrations remain below 1% of the lower flammability limit (LFL) in enclosed spaces, as higher concentrations pose explosion risks.

IEC 60079-10-1 classifies hazardous zones where explosive atmospheres may occur. In electrolysis plants, Zone 0 areas are locations where hydrogen is continuously present, such as inside electrolyzer stacks or gas ducts. Zone 1 areas are spaces where hydrogen is likely to occur during normal operation, including near fittings or valves. Zone 2 areas are locations where hydrogen is present only under abnormal conditions, such as during leaks. Electrical equipment in these zones must comply with IEC 60079 series standards, ensuring spark-proof or explosion-proof designs.

Ventilation requirements are critical to maintaining safe hydrogen levels. ISO 22734 specifies that natural or mechanical ventilation must achieve at least 12 air changes per hour in enclosed electrolysis rooms. Forced ventilation systems must be redundant, with backup power to ensure operation during outages. Hydrogen sensors must be installed at strategic points, particularly near ceilings where hydrogen, being lighter than air, tends to accumulate. Sensor placement follows ISO 26142, which recommends detectors at intervals no greater than 5 meters in high-risk areas.

Thermal management is another safety priority. Electrolysis operates at elevated temperatures, especially in SOEC systems, which can exceed 700°C. IEC 62282-8-101 provides guidelines for thermal insulation and cooling systems to prevent overheating. High-temperature components must be isolated from hydrogen-rich environments to avoid autoignition, which can occur at temperatures above 500°C.

Material compatibility is addressed in ISO 11114-4, which specifies materials resistant to hydrogen embrittlement. Electrolysis plants often use stainless steel or nickel alloys for piping and storage to withstand prolonged exposure to hydrogen. Seals and gaskets must be non-porous and chemically inert to prevent gas permeation.

Emergency shutdown (ESD) systems are mandatory under IEC 61511. These systems must activate automatically upon detecting hydrogen concentrations exceeding 20% of the LFL or upon power failures. ESD protocols include isolating gas production, purging lines with inert gases like nitrogen, and activating suppression systems if ignition occurs.

Personnel safety measures include training programs aligned with ISO 14001 and ISO 45001. Operators must be proficient in handling hydrogen emergencies, including leak containment and evacuation procedures. Personal protective equipment (PPE) such as flame-resistant clothing and hydrogen-compatible respirators is required in high-risk zones.

Maintenance protocols follow IEC 60364 for electrical safety during servicing. Before inspections, electrolyzers must be purged and verified as gas-free using calibrated detectors. Lockout-tagout (LOTO) procedures prevent accidental energization during maintenance.

For outdoor installations, ISO 16923 provides guidelines for spacing between equipment to minimize fire risks. Electrolysis units must be positioned at least 5 meters from ignition sources and 10 meters from public access areas. Enclosures for outdoor systems must withstand weather extremes while maintaining ventilation rates.

Noise control is addressed in ISO 9614, as electrolysis plants can generate high decibel levels from compressors and cooling systems. Soundproofing measures must ensure worker exposure remains below 85 dB over an 8-hour shift.

Corrosion prevention is critical in alkaline electrolysis plants due to the caustic nature of the electrolyte. ISO 8044 mandates regular inspections of tanks and piping for degradation, with cathodic protection systems installed where applicable.

Documentation and record-keeping are emphasized in ISO 9001. Electrolysis plants must maintain logs of safety inspections, incident reports, and equipment certifications. Audits are conducted annually to verify compliance with all applicable standards.

In summary, international safety protocols for electrolysis plants focus on preventing hydrogen accumulation, ensuring material integrity, and mitigating thermal and electrical hazards. Standards from ISO and IEC provide a comprehensive framework for design, operation, and emergency response, minimizing risks in hydrogen production facilities. Adherence to these protocols is essential for safe and reliable electrolysis plant performance.