In a parting shot on the last full day of the Obama administration, the Department of Energy issued a rule that outlaws even more light bulbs. A ban imposed in 2007 outlawed most incandescent light bulbs, in effect, by imposing certain efficiency standards on ordinary light bulbs. However, Congress managed to exempt three-way bulbs, bug lights, "rough service lamps," and some decorative bulbs, such as globe-shaped bulbs.
But with its late hour rule, the DOE has now redefined the words in the 2007 law, "general service lamp," to refer to many more types of incandescent light bulbs. In effect, light bulbs that had been exempted specifically by Congress are now no longer exempted.
Because of the new rule, three-way bulbs have been banned. They each have two different filaments and thus three different brightnesses. DOE has now ruled that my be covered. The government’s reason is as follows: "DOE expects these sales will likely increase since these lamps could be used as replacements for other regulated lamp types."
A few bulb types are still exempt, including bug lights and oven lights.
In so many words, DOE calculated that citizens may buy the now banned bulbs because they want to buy regular incandescent light bulbs instead of expensive LEDs or fluorescents.
While the rule does not go into effect for three years, it may lead domestic manufacturers to cease production or go out of business. It remains for the Trump administration to address the rule change.