Ensuring Hydrogen Purity for Fuel Cells

Why Sampling at the Nozzle Matters for Reliable, Standards-Compliant Hydrogen Systems

As the global energy landscape shifts toward cleaner and more sustainable solutions, hydrogen has become a pivotal fuel for decarbonizing transportation, industry, and power generation.

Among its most promising applications is the use of hydrogen in proton exchange membrane (PEM) fuel cells, which offer high efficiency and zero emissions for vehicles and stationary systems. However, the performance, safety, and longevity of fuel cells are critically dependent on the purity of hydrogen supplied—a requirement that is far more stringent than other industrial uses. Even trace levels of contaminants can cause irreversible damage, reduced operational efficiency, and compromised system reliability.

Ensuring hydrogen purity is not simply a matter of laboratory analysis; it demands a comprehensive approach that spans the entire value chain—from production and storage to transfer and dispensing. At each stage, hydrogen is vulnerable to degradation and contamination, making robust sampling and verification procedures essential.

In response to this environment, Sauhaib Filali, an application engineer at Swagelok Munich, who specializes in the clean energy market, authored this white paper as a technical guide for engineers, operators, and stakeholders involved in hydrogen infrastructure and fuel cell deployment. It explores the principles and engineering challenges of hydrogen sampling, reviews the relevant standards, and presents practical system architectures that support accurate and compliant fuel quality verification.

Read the Whitepaper

In this question-and-answer session, Sauhaib takes the time to explain the market, the reasons behind this white paper, and how it can help customers.

Q: Tell us about yourself and how you came to work in this industry.

A: I completed my first bachelor’s degree in mechanical engineering from Hassan II University of Casablanca (Morocco) in a French-language engineering program. But I was motivated to deepen my technical expertise and build an international engineering career, so I moved to Germany and earned a second bachelor’s degree in mechanical engineering from the University of Applied Sciences Berlin, where the curriculum is taught in German.

In my current role at Swagelok Munich, which I started in 2022, I support the design, documentation, and implementation of hydrogen fluid systems across the entire clean-energy value chain, including hydrogen production, distribution, storage, sampling, and on-vehicle applications. My work spans process engineering, P&ID development, component specification, developing 3D system models and assembly drawings, and onsite technical support for customers.

Additionally, I evaluate systems and components for compliance with international hydrogen regulations to ensure safe, standards-aligned system designs. And I regularly speak at industry events such as Hannover Messe and TankTech on hydrogen system design best practices, hydrogen fuel quality, sampling and safety standards.

Q: How do you see the hydrogen market, both now and in the future?

A: In my role as an application engineer, I’ve witnessed the global hydrogen market evolve rapidly. It has moved from bold political ambitions and early-stage experimentation to a more structured, standards-driven deployment phase. Electrolyzer capacity has grown significantly, and fuel-cell mobility is starting to gain traction across Asia and Europe.

Europe’s approach has especially impressed me, as it includes binding infrastructure targets. For example, the European Union’s Alternative Fuel Infrastructure Regulation (AFIR) regulation requires hydrogen refueling stations to be available every 200 kilometers along core transport routes by 2030.

That said, the market still faces real challenges. One of the biggest is the gap between deployment and reliability. Too many systems are being built without consistent attention to fuel quality or long-term durability. Hydrogen fuel cells are highly sensitive to trace-level contamination, and quality assurance was, until recently, often overlooked.

Now, I’m encouraged to see the industry addressing this. New standards like ISO 19880-9 are finally providing clear guidance for hydrogen sampling at the dispenser, helping ensure that what reaches the vehicle meets critical purity specifications. I’m optimistic that this shift will carry the hydrogen economy toward scalable, long-term success.

Q: What did you see in the industry that made you author this white paper?

A: I see a critical gap in how the industry understands hydrogen fuel quality requirements for PEM fuel cell stacks and the role of sampling in protecting them. Hydrogen fuel must be at least 99.97% pure, with only trace contaminants allowed. But many customers were unsure how to achieve that level of purity at the point of dispensing. Many were/are relying on the supplier’s certificate of analysis, without realizing that hydrogen quality can degrade during compression, storage, and dispensing.

Sampling is an essential engineering approach to verify that the hydrogen still meets the required specifications at the point of use. However, sampling is a complex process, and if it’s not done properly, it can lead to inaccurate results, non-compliance, or long-term damage to the system.