Something as simple as a drink cup has led to big environmental changes at Atlanta-based AT&T Mobility.

The nation’s No. 2 wireless carrier is now an industry leader in sustainability, company executives say. Using plant-based plastic, selling energy-efficient mobile phone chargers and reducing packaging material have cut nearly 500 tons of paper and plastic waste out of AT&T Mobility’s products in 2010 and 2011.

The company isn’t alone in using sustainable products. Verizon touts “green” stores, and Sprint has received accolades for being an environmental leader.

“The industry is getting better,” overall, said Michael Cowan, the company’s accessories director.

For AT&T Mobility, the real push started three years ago when Cowan was thirsty.

“I was served a drink out of cup that was compostable,” Cowan said.

The situation couldn’t have been better. Cowan is a self-proclaimed recycling fanatic and has a compost bin at home. At work, he’s in charge of how AT&T Mobility’s car chargers, phone cases, batteries and headsets are packaged, which typically is in thick, plastic cases with lots of extra paper and other material.

So the compostable cup got him talking.

“We investigated that (to find that) it was a slightly different type of plastic.”

Drawing inspiration from fellow Atlanta giant, Coca-Cola Co., and its “plant bottle,” — a recyclable bottle made from material that’s partially made from plants — AT&T Mobility since 2011 has put its branded wireless accessories in packages of material that is 30 percent plant based. The so-called plant plastic material comes from ethanol that is harvested from natural sugarcane.

Using sugarcane replaces nearly one-third of the fossil fuels traditionally used in this type of packaging, according to the company.

Cowan says the plant plastic is actually more expensive but the overall efforts to cut out waste and become more energy efficient saved the company $42 million in 2011, according to AT&T Mobility data. The packaging for car chargers — once a thick plastic shell inside another paper box — shrunk 60 percent, for example. The paper used inside boxes and plastic packaging is 100 percent recyclable stock, and the ink is based from vegetables instead of petroleum.

Executives also challenged its vendors to make mobile phone chargers that don’t draw electricity from outlets when they are left idle. The more efficient chargers save electricity and customers money on their phone bills when added up over time, Cowan said.

Personally, the efforts for Cowan were easy. He grew up collecting cans to recover the money from recycling them. At Georgia Tech, he pushed the student government to switch to recycled paper.

“I’m a fanatic about it,” said Cowan, who takes trash back from vacations to recycle at home. Same goes for family holidays and visits; he always leaves with a bag of cans, bottles, food, napkins and other items to recycle or compost. “My wife used to make fun of me and complain about that we always brought back garbage. Now she’s been a big recycler like I am.”

Moving forward, AT&T Mobility is creating a “score card” for devices and accessories to see how the material in the product stacks up against sustainable goals. One idea is to do more business with vendors, suppliers and manufacturers in North America, reducing the amount of materials that need to be transported, which Cowan says puts a large strain on the environment.

“The next big breakthrough, I’m not sure, but we’re looking for it,” he said.