As famed blue jeans brand Levi Strauss celebrates the 141st birthday of the 501 jean, the company’s CEO says he wants Levi to become “the ultimate in sustainable apparel.”

In an interview with Fortune at the Brainstorm Green conference in Laguna Niguel, Calif., CEO Chip Bergh said he want’s Levis jeans to “last a lot longer than most people’s waistlines.”

Bergh’s goal comes at a time of “throwaway” fashion trends made popular by low-cost retailers like H&M.

Levi is far ahead of the curve when it comes to sustainability. Berg said the clothes are made with much less energy and water out of fabrics that are easier to recycle. They are also manufactured in plants where workers well-being is measured and meet high standards.

Bergh also wants you to do your part for sustainability — stop washing your jeans.

“These are one of my favorite jeans. These jeans are maybe a year old and these have yet to see a washing machine. I know that sounds totally disgusting. I know it does. But believe me, you can spot clean it, you can air dry it and it is fine. I have yet to get a skin disease or anything else. It works,” Bergh said.

The company is also making new “waterless” jeans. Those jeans will get that acid-wash look without using harsh bleach or chemicals.