It’s Light! When hydrogen escapes into the atmosphere, it is so light that it scatters immediately upward in the air (it’s 14 times lighter than air). This means that a hydrogen spill won’t pool on the ground, pollute groundwater, or soak into clothing—it removes itself!

It’s Everywhere! Hydrogen is the most abundant element in the universe, making up more that 90% of all matter. On Earth, it is the third most abundant element in the Earth’s surface, found in water and all organic matter.

What’s Its Nature? In its normal gaseous state, hydrogen is colorless, odorless, tasteless, and is nontoxic, which makes it different from every other common fuel we use.

What Happens When Hydrogen Burns? Hydrogen burns readily with oxygen, releasing considerable energy as heat and producing only water as exhaust. When hydrogen burns in air (which is mostly nitrogen), some oxides of nitrogen (NOx, contributors to smog and acid rain) can be formed, but much fewer pollutants are formed than when normal hydrocarbon fuels such as gasoline and diesel are burned. Because no carbon is involved, using hydrogen fuel eliminates carbon monoxide, carbon dioxide, and does not contribute to global warming.
 
 

References:

--website: http://www.hkbu.edu.hk/~matsci/Periodic_Table/elements/H.htm#Basic

--DOE Website: http://www.eren.doe.gov/hydrogen/basics.html

--Clean Air Now Website: http://www.ch2bc.org/spotlite/CANspot/CANSPOT.htm