There is a straightforward element of danger in hydrogen especially when reflecting on the Hindenburg blimp disaster. In-depth details might show, there were other aspect of the fire, than simply hydrogen igniting, however, the incident still remains a bench-mark in history, that gives wariness to hydrogen use for public transportation.
Testing has been done on hydrogen vehicles. The big question set forth here is, has there been enough testing to cover different angles of hypothetical scenarios that might not have been. Unknown variables, might be a term that sums up an area of focus that could be elusive, albeit is vital to safety.
"Today's hydrogen fuel tanks are also made from highly durable carbon fiber whose strength is assessed not only in crash tests but also in trials in which bullets are fired at it." [http://www.computerworld.com/article/2852323/heres-why-hydrogen-fueled-cars-arent-little-hindenburgs.html]
Take for example the following scenarios:
- High speed collisions, where a driver was racing in speeds beyond 100mph
- Collisions involving crushing, such as the hydrogen car with a large truck, where it really does not matter how tough the hydrogen encasement is, bullet proof or otherwise; an 18 wheeler travelling 75 mph that slams into the back of an average sized sedan, especially when trapped between something else, another truck, a hill at an embankment, the casing and the car is likely going to be crushed; when that happens hydrogen will also probably escape.
- Fuel or fire from another vehicle that is not a hydrogen vehicle, in a collision situation, and the hydrogen leak shut-off mechanism is not activated. This refers to a scenario where flames or sparks can still react with the hydrogen, but were not enough to trigger hydrogen safety features.
- Perhaps some of the largest dangers are dangers in the unknown. When the safety feature is compressing the surrounding hydrogen case even tighter, does that make the pressure on the hydrogen, in some sense or ways, even greater, making it even more of a danger if there is a string enough of an impact on it to cause an after-effect?
- E=mc squared, and spray-starch cans in reference, the more pressure packed into the container, the stronger the release, perhaps.
Reactions are not just limited to fire.
Children sleeping in the car in garage, when the motor is running, is something that might be worth looking into.
Unfortunately, in this day and age, we have to look at situations that are extreme, and involve using the equipment in ways that are divergent from a trustworthy driver.
With that, laws that penalize for tamperment (tampering) with hydrogen safety mechanisms, might be an idea. Such effort would preclude usage of hydrogen vehicles for other uses not in the best ideal of humankind.
"At last week's Los Angeles Auto Show [article written November 26, 2014], several major car companies, including Audi, Honda, Hyundai and Toyota, announced the release of, or updated plans to release, hydrogen fuel cell vehicles this year or within the next two years." [http://www.computerworld.com/article/2852323/heres-why-hydrogen-fueled-cars-arent-little-hindenburgs.html]
Dangers Overview [courtesy What are the dangers of hydrogen-powered vehicles? ]:
Topping the list of concerns is hydrogen burns. In the presence of an oxidizer -- oxygen is a good one -- hydrogen can catch fire, sometimes explosively, and it burns more easily than gasoline does. According to the American National Standards Institute, hydrogen requires only one 10th as much energy to ignite as gasoline does. A spark of static electricity from a person's finger is enough to set it off. Ideally, no oxygen should be present in the liquid hydrogen tanks in a fuel cell vehicle, but trace amounts of air may contaminate the hydrogen supply. If the hydrogen should escape, it will immediately come into contact with the oxygen in air.
Another concern is that hydrogen flames are nearly invisible. When hydrogen catches fire, the flames are so dim and hard to see that they're both hard to avoid and hard to fight.
Next, there's the potential for hydrogen to asphyxiate people. Hydrogen isn't poisonous, but if you should breathe pure hydrogen you could die of asphyxiation simply because you'll be deprived of oxygen. Worse, you won't necessarily know that you're breathing hydrogen because it's invisible, odorless and flavorless -- much like oxygen.
The final concern that we want to mention here is that liquid hydrogen is cold. Because it's highly compressed, liquid hydrogen is extremely cold. If it should escape from its tank and come in contact with skin it can cause severe frostbite.
[http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/hydrogen-vehicle-danger1.htm]
Other Dangers Brought to Forefront
The key theme of this entire article, considering that there have been numerous articles about safety hazards pertinent hydrogen vehicles, are situations that have not been tested for, and might not be apparent as a danger, until a real situation happens. Maximizing ranges of scenarios for safety testing might minimize dangers, however, getting to them all is just like gasoline and electric vehicles, work will have to continue as an ongoing effort.
Confer 'Safety issues regarding fuel cell vehicles and hydrogen fueled vehicles'
"Hydrogen also has many characteristics that warrant its being handled with great care. Hydrogen-air mixtures can ignite or explode at both lower and higher concentrations of the gas (1) in the air than CNG or methane. Hydrogen is more easily ignited than other fuels. The impact of this is negligible, however, as most other fuels can already be ignited by small amounts of static electricity." ]
III. Areas of Concern The two prime dangers from fuel cell and hydrogen-powered vehicles are the danger of electrical shock and the flammability of the fuel.
Outline of other concerns:
- Electric current
- Electrical Drive System
- Internal fuel transmission and consumption
- Thus, the main fuel-related issues for fuel cell safety regard the use of hydrogen. While being a very clean and energy-dense fuel, hydrogen has the tendency to disperse quickly under normal pressure.
- Fuel Storage
- Fueling
- Maintenance
- Parking of the vehicle
- Parking a hydrogen vehicle or other gas-fueled vehicle in an enclosed structure is a serious safety concern as it can lead to a buildup of the gas. Hydrogen’s tendency to rise and disperse rapidly makes this the only situation in which small leaks can create extremely dangerous situations.
- Emission
- Detection
Regarding detection, is seeing a fire when there is a fire; when a fire cannot be seen, it might be harder to put out, or respond to.
Situations that occur, when all safety precautions have been taken, everyone has done what they were supposed to, and abided by all laws, but, an accident happens anyway; are we ready for these scenarios, with hundreds or thousands of hydrogen cars on the roads in the next few months?
"...Fiery explosion August 26 at a General Motors-owned hydrogen station at the Greater Rochester International Airport (causing it to be briefly closed). Two people were injured, one of them seriously enough to require hospitalization.
The incident was sparked (which may be the right word) when an employee... was switching out one of the station's large hydrogen tanks. It's unclear what happened, since the worker (who will fully recover) was following proper safety procedures. O'Connell thinks some kind of equipment failure may have occurred." [2010 article http://www.cbsnews.com/news/a-hydrogen-explosion-rattles-nerves-but-fuel-cell-cars-have-a-good-safety-record/]
Additions and edits to this article might be performed in the near future
