On Tuesday, May 20, Levi’s 501 jeans celebrated their 141st birthday. These jeans are some of the most popular jeans in the world, along with the most durable.

While speaking at Fortune’s Brainstorm Green conference in Laguna Niguel, California, Levi Strauss’ CEO Chip Bergh explained why the Levi brand has survived so many years, and plans on surviving for many more years to come.

“We are the ultimate in sustainable apparel,” Bergh said. “If you buy [our jeans] they will last a lot longer than most people’s waistlines will.”

Not only are the jeans more durable than most, they are also produced in a much greener way. The production of the jeans uses less energy and water, and are made out of fabrics that are easier to recycle. Levi’s also provides an impeccable work environment for their employees, and focusses on their overall well-being.

One of Bergh’s most innovative ideas for making your Levi’s last longer is something that will come as quite a shock to most people. Bergh advises customers to STOP washing their jeans! “These jeans have yet to see a washing machine,” Bergh said of the jeans he was wearing during the interview, which he admitted that he had owned for a full year. “I have yet to get a skin disease.”

So, if you don’t wash your jeans, how do you get rid of the stench? Experts recommend spraying white vinegar or vodka on your jeans and then hanging them outside to air dry. Another option is to freeze your jeans. Yes, that is right, turn your jeans inside out and freeze them for 24-48 hours. Both of these ideas will eliminate the smell of bacteria, and any other odors.

Image via Wikimedia Commons