"Despite strong, on-going sales of 4-foot T12 fluorescent lamps, the magnetic ballasts commonly used for the lamps’ operation will start becoming relics of the past on July 1, 2010, when their continued manufacture for commercial and industrial applications becomes prohibited by U.S. Department of Energy (DOE) ballast efficiency regulations.
According to the National Lighting Bureau, the July 1, 2010 date marks the last step of a multi-step phase-out that began on July 1, 2005, the date when ballast manufacturers could no longer sell T12 magnetic ballasts for use in new fixtures with full-wattage T12 lamps. March 31, 2006 was the last day lighting-fixture manufacturers could incorporate the ballasts in new fixtures with full-wattage T12 lamps. And on July 1, 2010, the manufacture of T12 magnetic ballasts solely for replacement purposes will cease."