Are Hydrogen Cars Safe?

Hydrogen cars might seem like a new phenomenon, but the tech is actually older than so-called “conventional” fuels. Still, one of the biggest impediments to broader hydrogen fuel adoption is widespread concern over its safety as a fuel source. These fears are ultimately misplaced, as hydrogen fuel cells feature comparable (if not preferable) safety standards relative to conventional fuels.

Below, we’ll break down why hydrogen is a safer fuel option than you might realize, covering:

• The underlying technology that powers hydrogen fuel cell cars
• Some common misconceptions about hydrogen being unsafe
• The factors that make hydrogen a relatively safe fuel for cars
• A safety comparison between hydrogen and conventional cars
• A peek into what the future holds for hydrogen cars and safety

How Hydrogen Fuel Cell Technology Works

The technology that powers hydrogen fuel cell vehicles might seem complicated, but it’s a relatively straightforward process. And its simplicity is also a major component of why hydrogen is such a safe resource.

In a fuel cell electric vehicle (FCEV), hydrogen gas travels to the fuel cell with an anode, cathode, and electrolyte membrane. Then, a negative charge from the negative anode splits hydrogen (H2) into ions (2H+). The H+ ions naturally move toward their negative counterparts, oxygen ions (O-) in the air, and they bond. This process forms the water (H2O) byproduct commonly associated with hydrogen cars’ exhaust pipes, a stark contrast to conventional exhaust smog.

But it’s the free electrons separating from the H2 that create the energy—an electrical charge—that powers these vehicles. More specifically, conventional fuel cells can provide ~330-400 miles of range for about ~6kg of fuel for efficient, clean, and safe transportation.

Debunking Myths About Hydrogen Car Safety

While some people are concerned about the safety of hydrogen fuel, their underlying assumptions are often inaccurate. Hydrogen indeed requires less energy than other fuels for ignition, so there are lower barriers to entry, so to speak, for flammable conditions. However, according to the Natural Resources Defense Council (NRDC), hydrogen fuel is still safe because it has a lower radiant heat and a higher oxygen requirement for explosion than conventional gasoline.

Another common misconception comes from an overemphasis on one infamous historical example without appropriate consideration of new innovations around hydrogen. People associate H2 fuel with explosions because of the 1937 Hindenburg disaster, in which a hydrogen-powered airship exploded and killed 36 people. But this association is not logically sound, as hydrogen fuel cells share little, if anything, with the specific design of this nearly century-old vehicle.

Today, manufacturers working on hydrogen fuel cell cars pack them with safety features and redundancies that account for potential weaknesses. And, beyond that, H2 is inherently safe.

Key Safety Features of Hydrogen Vehicles

The biggest safety feature of hydrogen fuel-powered cars is the fact that, for now (see below), they do not rely on combustion. DriveClean (of The California Air Resources Board) explains that what makes hydrogen-powered cars work is a safe chemical transfer—without burning fuel.

The US Department of Energy’s primer on safe hydrogen use illustrates two other reasons that hydrogen fuel can actually be much safer than other common fuels when used appropriately:

• Hydrogen is non-toxic – Hydrogen is completely non-toxic and non-poisonous to humans, which means that working with it entails fewer threats than fossil fuels.
• Hydrogen is lighter than air – Because of its weight, hydrogen dissipates exceptionally quickly, which aids rapid and safe dispersal in case a leak or other issue occurs.

The Department of Energy also notes that hydrogen is quite flammable (see above). Despite being non-toxic, hydrogen can make metals exposed to it brittle. However, even with these considerations, hydrogen-powered cars make sense from a safety perspective because the underlying properties of hydrogen fuel make them safe, if not safer, than other cars’ fuel sources.

Hydrogen vs. Traditional Cars: A Safety Comparison

As noted above, many of hydrogen fuel’s potential safety concerns are accounted for in the design of modern hydrogen fuel applications—much like firewalls in conventional fuel cars.

So, here’s a breakdown of how hydrogen fuel safety stacks up against its main competition:

Hydrogen Fuel Cars

• Not toxic or poisonous to humans
• High flammability, low radiant heat
• Lightness and rapid dissipation
• High O2 requirement for explosions

Conventional Fuel Cars

• Toxic and/or poisonous to humans
• High flammability, high radiant heat
• Heaviness and slower dissipation
• Low O2 requirement for explosions

There are also other electric vehicles (EVs) to consider, namely battery electric vehicles (BEVs), which compare similarly to HCEVs because they also do not use combustion. The main safety concerns revolve around the lack of obvious engine noises, which can put pedestrians at risk (these cars often emit simulated engine sounds by default to counteract this). Additionally, there are growing concerns about the proliferation of heavy EVs with higher risk profiles.

On another level entirely, there’s a consideration of planet-wide safety.

It’s common knowledge that H2 fuel cells are more environmentally friendly than conventional fuels. If more automakers shift to a hydrogen-first model, the transportation industry's impact on climate change will make the world safer for every inhabitant—not just drivers.

The Future of Hydrogen Car Safety

Looking ahead, innovations in hydrogen fuel cell technology will only make the fuel source even safer than it is already. And, over time, public perception will (hopefully) catch up to reality.

One of the most significant advancements to this effect is graphene, which will make hydrogen fuel cells more durable in the future. A long-standing hurdle to wider hydrogen adoption is that its storage requires precise conditions (temperature, pressure, etc.). These conditions, paired with corrosive elements in the environment and hydrogen’s embrittling nature, have led to poor durability in the materials used to store, transport, dispense, and use hydrogen fuel.

As a side effect, poor durability is a concern with respect to leaks that could lead to disasters.

Thankfully, graphene has the potential to solve this problem. Current prototypes boast 30% better performance in rigorous testing, and this is still early in the research and development process.

Other exciting developments include new and innovative hydrogen fueling solutions, such as Toyota’s hydrogen combustion engine. Though avoiding combustion is a major boon to hydrogen fuel cells’ safety, safe hydrogen combustion could be a whole new frontier.

And, to return to the point of planet-wide safety, increased hydrogen fuel adoption is one approach to building renewable energy resilience and maximizing global sustainability.

Unlocking Safety and Efficiency at Scale

Looking ahead, people are going to stop asking if hydrogen fuel cell cars are safe. With greater market saturation, more people will be able to see that they are. The question will evolve into bigger implications: How safe can they be? Are non-hydrogen cars safe to drive?

For our part, FASTECH is committed to the promise of hydrogen fuel for a safer and more sustainable future. We offer renewable energy Engineering, Procurement & Construction (EPC) services to organizations looking to get the most out of this reliable, efficient energy source.

To learn more about how we can help your organization, get in touch today!

Sources:

DriveClean. Hydrogen Fuel Cell Electric Cars. https://driveclean.ca.gov/hydrogen-fuel-cell

Hydrogen Fuel News. What makes Toyota’s hydrogen combustion engine special? https://www.hydrogenfuelnews.com/hydrogen-combustion-engine-toyota-2/8556753/

Insurance Institute for Highway Safety. As heavy EVs proliferate, their weight may be a drag on safety. https://www.iihs.org/news/detail/as-heavy-evs-proliferate-their-weight-may-be-a-drag-on-safety

Natural Resources Defense Council. Hydrogen Safety: Let's Clear the Air. https://www.nrdc.org/bio/christian-tae/hydrogen-safety-lets-clear-air

US Department of Energy. Safe Use of Hydrogen. https://www.energy.gov/eere/fuelcells/safe-use-hydrogen