Pure neon gas with NO MERCURY produces the familiar red neon glow. There is NEVER mercury added to these tubes. Not now, not in the 1930′s. Pure neon gas is also used to make various shades of orange-red-pink, etc. Again, no mercury at all in such tubes. Not even a pico-gram. Doing such would ruin the tube’s color.

Other shades of “neon” operate identical to a flourescent lamp, but have a cold-cathode electrode instead of a heated filament. These tubes are cold cathode flourescent… though many just use the word “neon” as a general term for such custom-formed lamps.

Yes, these tubes have mercury to activate the phosphor coating, and vastly increase lumen efficiency. And correct – such tubes have generally more “Hg than typical hot-cathode flourescent lamps. However, the same technologies hot-cathode lamps use to reduce Hg content are now filtering down into the neon industry as well:

But there is more to the Hg story. The truth is that LEED correctly calculates mercury content in picogram/lumen hour http://leed-eb.leonardoacademy.org/sustain_calc.php . In this way cold cathode can be calculated as having a substantially reduced Hg environmental impact over CFL and potentially over low Hg linear hot cathode.

Thank you ,
Regards, Wendy buyer for The Manitoba Museum Shop

Pure neon, with nothing else, gives you the deep red color that is so familiar. It is in neon sign tubes at a pressure of around 15 mbar for this effect. In other words, mostly a vacuum with a small amount of pure neon added.

BTW, you can also make many colors now in a “neon type” tube without mercury by using pure Xenon gas. This works especially well for green, blue, turquoise, purple, etc. Adding Hg does boost the efficiency significantly however. For lots of light and low power requirements, Hg (unfortunately) hasn’t found a replacement.