NATCHEZ — Ricky Long is only a few months away from selling the last incandescent light bulbs in stock at Natchez Electric and Supply Co.

The store manager doesn’t have anything against the standard light bulb that’s illuminated households across the world for more than a century.

But the switch was flipped years ago.

On Wednesday, it became illegal to manufacture or import 60- and 40-watt incandescent bulbs through federally mandated efficiency standards signed into law in 2007.

The law was aimed to “move the United States toward greater energy independence and security,” according to the Energy Independence and Security Act of 2007.

The efficiency standards started with 100- and 75-watt bulbs being phased out in earlier stages.

“We’ve known this was coming, but it’ll still be weird when the last one is gone,” Long said. “They were the standard for so long and something everyone knows about.”

The standards aimed to stop light bulb makers from producing the old tungsten filament bulbs and switch to more energy efficient designs, such as compact fluorescent light bulbs (CFLs), light-emitting diodes (LEDs) or halogen bulbs.

The incandescent light bulb, perfected for mass use by Thomas A. Edison in the late 19th century, began being supplemented in 2007 by fluorescent lighting that was more efficient and longer lasting.

The standards don’t include three-way bulbs, 150-watt bulbs and bulbs with a narrower base, such as the ones used in chandeliers.

Fluorescents, which create light by heating gases inside a glass tube, were developed in the early 20th century and sold publicly by the 1940s. They are generally considered to use more than 50 percent less energy and last several times longer than incandescent bulbs. The mercury vapor inside fluorescents, however, can damage the environment if the bulbs are broken.

The fluorescent light bulbs, sometimes referred to as “twisty” or “spiral” bulbs, have become the norm for a majority of customers since the incandescent faded out, Long said.

A traditional incandescent bulb burning three hours a day would last 1.4 years and cost $7.23 in yearly energy cost. A fluorescent bulb burning the same amount of time would last 5.5 years and cost $1.57 in yearly energy cost, according to Energy Star.

“The fluorescents are the easiest switch because of the cost,” Long said. “They don’t’ cost as much as the old incandescent and they do last longer and use less power.”

LED lights are becoming the second most popular alternative to incandescent, Long said, because of how long they last and energy saving benefits.

LEDs are estimated to use 70- to 80-percent less power than an incandescent bulb and generally last between 35,000 to 50,000 hours.

“They cost a little more up front, but it all balances out with how much lower your energy bill will be,” Long said. “And now that incandescent bulbs are out, LEDs should go down in price.”

Glenn Etheridge of Home Hardware said local stores stocked up on incandescent light bulbs a few weeks ago in anticipation of the Jan. 1 mandate.

While the stores will have bulbs on the shelves for a few more months, Etheridge said customers rarely notice the absence of the 100- and 75-watt bulbs.

“I would say about a third of them know they’re missing and ask about it,” Etheridge said. “Most of them come in looking for the fluorescent twist bulbs, but some amazingly notice the change and ask where they are.

“It’s a generational thing though — the younger folks are used to the change and the older folks are catching up.”

The Associated Press contributed to this report.