Hydrogen has many applications and uses. Hydrogen mixed with inert gas can be used in annealing stainless steel alloys and magnetic steel alloys, sintering, and copper blazing, It has also its uses in chemical, pharmaceutical and petroleum processes. But in the Philippines, the most common use of hydrogen is as lifting gas in balloons because of its properties. Hydrogen is the lightest of all gases, approximately one fifteenth as heavy as air. Hydrogen ignites easily, together with oxygen or air it forms an explosive gas.