What is the explosive range of hydrogen?
Hydrogen has a very broad flammability range—a 4 percent to 74 percent concentration in air and 4 percent to 94 percent in oxygen; therefore, keeping air or oxygen from mixing with hydrogen inside confined spaces is very important.
Is hydrogen highly explosive?
Hydrogen can be explosive at concentrations of 18.3% to 59%. Although this range is wide, it is important to remember that gasoline can present a greater danger than hydrogen because the potential for explosion occurs with gasoline at much lower concentrations: 1.1% to 3.3%.
What is the lower flammability limit of hydrogen?
about 4%
The lower flammability limit of hydrogen is about 4% by volume and the upper limit is about 75% by volume.
What is the lower explosive limit of hydrogen in ppm?
41,000 ppm
However, the lower explosive limit for hydrogen in air is 41,000 ppm, and 10% of this concentration is 4,100 ppm.
What is the upper explosive limit?
The highest concentration of a gas or vapor (percentage by volume in air) above which a flame will not spread in the presence of an ignition source (arc, flame, or heat). Concentrations higher than UEL are “too rich” to burn.
Is Earth the only planet where fire can burn?
Earth is the only known planet where fire can burn. Everywhere else: Not enough oxygen. Air is 21 percent oxygen; combine pure oxygen with acetylene, a chemical relative of methane, and you get an oxyacetylene welding torch that burns at over 5,500 degrees Fahrenheit — the hottest fire you are likely to encounter.
What is hydrogens reactivity?
Atomic hydrogen is very reactive. It combines with most elements to form hydrides (e.g., sodium hydride, NaH), and it reduces metallic oxides, a reaction that produces the metal in its elemental state. Almost all metals and nonmetals react with hydrogen at high temperatures.
What is a safe level of H2S?
The Occupational Safety and Health Administration (OSHA) defines Permissible Exposure Limits (PELs) to H2S gas as follows: General Industry Ceiling Limit: 20 ppm. General Industry Peak Limit: 50 ppm (up to 10 minutes if no other exposure during shift) Construction 8-hour Limit: 10 ppm.