Courtesy of the Klein family

Sam Klein donates groceries to the Ronald McDonald House.

By Kevin Tibbles, NBC News correspondent

ST. LOUIS, Mo. -- Heidi Klein realized something was up when she got a call from the local waste management company.

“May I speak to Sam Klein please?” the caller asked.

“Well, actually he’s in kindergarten at the moment!” she replied, startled.

Her son Sam had not only been waiting on a lawn chair each week for the garbage truck to roll by; he’d also befriended the garbage men and started dialing the number of the company to compliment their work ethic. All this at the ripe old age of five. 

Soon, with his parents’ permission of course, Sam was helping them load the truck, taking a ride in the truck … he even had his birthday party at the waste disposal facility. Shortly thereafter, Heidi said, Sam got an idea.

While some kids make a little spare change by opening a lemonade stand, Sam started visiting local businesses in St. Louis, Mo., and asking for their empty inkjet cartridges. He takes them home to his bedroom-cum-head office, and spends about 10 hours a week packaging them up in a shipping box and sending them off to the manufacturers.

He is now 12 years old and running his own recycling business.

“Did you know that each person [on the planet] throws out four and a half pounds of trash a day?” he asked. “Now multiply that by 3.8 billion people! How many pounds is that?”

(Math was never my strong suit; but I am willing to acknowledge it’s a lot.)

So this middle school impresario is now doing his bit to green the world from his second-floor room. Better still, the cartridge manufacturers are paying him for the recycled material -- anywhere between $20 to $200 depending on the type and number of cartridges he collects. He does admit, however, that his parents do get a tad upset with him from time to time over the ink stains on his bedroom carpet.

But Sam Klein wasn’t satisfied.

Sure he was helping out the environment, but what could he do to help his fellow man?

He says he’d feel selfish if he was pocketing all the money from his recycling business. So he’s been donating it to various organizations in and around St. Louis, such as the Ronald McDonald House, and asking grocery stores to donate, too. He is particularly interested in helping the homeless, which is something his mother finds very telling.

“It hurts him,” Heidi Klein said. “It hurts him to see someone tossed aside. Whether it’s a person or it is garbage it is not right.”

Sam, who has so far gathered about $1,000 in aid for those who are less fortunate, agreed. He looks at all the people and things that society has no further use for and sees something of value.

“When you throw something away … it hasn’t gone away,” he said.  “It’s just gone to a different location.”