Fluorescent tube lighting has long been the lighting option of choice for a wide range of commercial buildings, due to the fact that it’s more energy efficient than using incandescents. But as U.S. lighting standards have tightened up all around (with some notable instances of back-sliding), the good old T-12 tube is now going the way of the dodo.

United States lighting manufacturers will cease production on T-12 lamps next month in compliance with an energy efficient lighting mandate released by the Department of Energy (DOE). This mandate — part of a suite of such decisions that also predicated the phase-out of the 100-watt incandescent this year — was designed help the nation curb its carbon emissions habit by removing outdated lighting tech from the marketplace. The DOE’s mandate required magnetic ballasts, used in T-12 fixtures, to be phased out of production in July 2010; with the last of those magnetic ballasts accounted for, manufacturers will now cease production.

image via Shutterstock

That’s good news for the environment. Sure, those old-fashioned fluorescents in the commercial sector didn’t suck up as much juice as their residential, incandescent cousins, but the commercial sector also keeps its lights on far longer, with most commercial fluorescent lamps seeing as much as 11 hours a day of service.

Beyond being inefficient on the energy front, T-12′s also have shorter lives, poorer color rendering and lower lighting output than more efficient fluorescent alternatives, such as the T-8 or T-5. According to SmartWatt Energy, retrofitting from a T-12 to a T-8 or T-5 fluorescent lighting system is a simple way to reduce energy consumption by up to 45%, producing substantial energy cost savings at a payback period between one and three years. (These energy efficiency upgrades may also qualify for tax deductions and utility rebates, further reducing the payback period and initial cash required to upgrade.)

And for companies that continue to drag their feet, higher costs will soon become a reality anyway, as the T-12 fluorescent, come July, is due to become something of a collector’s item.