Natural gas is colorless and odorless, so mercaptans are commonly added to the gas to aid in detection of leaks. Many laboratories are equipped with natural gas supplied through valves on the benchtops, if a pungent odor reminiscent of garlic is detected in the laboratory from a source that cannot be identified; stop all work, locate the emergency gas shutoff and turn the valve off, evacuate the laboratory and contact work control at (703)993-2525, to report the leak.
Situations involving uncontrollable leaking gas from a cylinder should be considered extremely hazardous and may warrant immediate evacuation of the building. If the gas leak is minimal, innocuous, and safely within reach, the cylinder valve should be closed. Otherwise leave the area, call the Police by dialing 911, and activate the fire alarm to evacuate the building. If you are working with acutely toxic or flammable gases and suspect that a cylinder is leaking or gas is being released into the work area, evacuate the building immediately by activating the fire alarm. Once in a safe location, contact the Police by dialing 911 and report the situation.