The new bags are designed to replace the paper or plastic ones given to customers at the time of purchase, said Pam Smith, Navy Exchange Bethesda and Washington general manager. Customers have the choice between the 99 cent non-insulated bags or the $1.99 insulated version. They can be brought back to the store multiple times to reduce the need for non-eco-friendly alternatives, Smith said.

The new bags have a flat bottom to prevent items from tipping over, Smith said Shoppers can recycle the bags when they’re no longer usable, she said. The 100-percent polypropylene bags are also moisture and stain resistant.

‘‘The [Navy Exchange] is always looking for ways to help the environment and make the shopping experience a pleasant one for our customers,” said Mike Mongin, Navy Exchange Command operations program manager.

Marcia Tyrell, a Bethesda Navy Exchange shopper, said, ‘‘I don’t like plastic bags because they always rip when I have heavy items.”

Another shopper, Megan Donnelly, said she recycles, but doesn’t know if she is as concerned about the environment as she should be. The bags, she said, may be something that will get her to become more eco-conscious.

Tyrell said she already owns an insulated bag bought from a local grocery store. She said she frequently uses it to store her milk and frozen foods in when she can’t go directly home.

Tya Simon, Bethesda’s visual department manager said, the zippered, insulated bags sold out not long after they were put on display. The non-insulated bags also sold so well, she said, that the store had to put in another order one week after it’s initial release.

Some local grocery stores offer price deductions for customers who bring in their own bags, but Kristine Sturkie, Navy Exchange Service public affairs specialist, said they have not considered following suit — yet.

Sturkie said the Exchange is continuously working on ways to become more environmentally conscious. Along with the newly-incorporated bags, she said the exchange is also reducing energy consumption in regular and distribution stores.

The Navy Exchange, who controls vending machines on naval installations, plans to install temperature and power-down sensors in their machines. They will also be opening bio-diesel gas stations, providing a clean burning alternative fuel from renewable resources.