Levi Strauss CEO Chip Bergh has disclosed that jeans are never meant to be washed.

“We’re trying to educate the consumer,” a double-denim wearing Mr Bergh told Fortune magazine’s Andy Serwer.

Talking about his own pair of jeans that are a year old, he said they are “yet to see a washing machine”.

“I know that sounds totally disgusting. I know it does but believe me it can be done. You can spot clean it, you can air dry it, and it’s fine. I am yet to get a skin disease or anything else, it works.”

“If you talk to real denim aficionados they’ll tell you don’t wash your blue jeans, just take a sponge or toothbrush.”

Mr Berg, who used to run Proctor & Gamble’s Gillette business, said the company is trying to be the ultimate in “slow fashion” in contrast to the throw away mentality of clothing giants such as H&M.

“We are the ultimate in sustainable apparel. We build our products to last, if you treat ‘em right they will last you a long time — probably longer than most people’s waistlines,” he said.

The company has created a range of Wellthread products which use less energy and water and are easier to recycle. They’re also producing a line of “waterless” jeans which achieve the acid-wash look without using harsh bleach or chemicals.

Levi’s 501 jeans turned 141 yesterday.