Xenon is a colorless, odorless gas that occurs naturally in trace amounts of the earth's atmosphere. It is the 54th element on the periodic table, with the symbol Xe, and is one of six elemental gases known as the noble gases. The noble gases--which also include helium, neon, argon, krypton and radon--all are stable and nonreactive elements because of their chemical structure. Xenon is a heavy gas, and breathing it in causes the voice to lower in pitch, much like the light helium raises the voice's pitch. While xenon itself is non-toxic, it can cause anesthesia and suffocation when inhaled.
In the same manner that its sister noble gas produces the famous neon lights of Las Vegas, xenon amplifies light that two electrodes produce when electricity jumps between them. Unlike the eye-catching reddish glow produced by electrically charged neon, xenon produces a bluish glow, emitting a light that is similar to daylight. True xenon lights produce their glow from the charge and the gas alone and do not include a filament.
High-intensity discharge xenon lights are becoming increasingly common as automobile headlights. They first appeared on select BMW vehicles in 1993 and since have become accessories for a number of high-end auto manufacturers as well as a proliferating add-on for car owners at large. Xenon lights also are used in a number of other settings, including operating rooms, stage lights, plasma display panels and high-intensity approach lights for aircraft.
Manufacturers tout xenon lights as a safer, more durable and energy-saving alternative to halogen lights in automobiles. Xenon bulbs increase the viewing radius over halogen lights by about 70 percent, and they are about three times brighter than the standard halogen light. They generally last about 10 years, three times longer than the standard halogen bulb, and consume only three-quarters of the power. The ultraviolet light produced by the headlights reflect brightly off highway signs, too.
A common complaint about xenon lights is that their powerful glow is a blinding distraction to other drivers on the road. Manufacturers contend that halogen headlights received the same criticism when introduced a few decades ago, but auto manufacturers like Mercedes-Benz and Infiniti have added leveling technology to keep the lights at angles that do not blind other drivers. Xenon lights also remain prohibitively expensive for many drivers, usually coming as part of premium packages on already costly cars. Several companies produce xenon lights as do-it-yourself installations, though some of these are copycat products that, while containing xenon and producing a blue glow, have filaments and are not true xenon lights.