Is It Sanitary to Not Wash Your Levi's Jeans?

Business Insider
Analyzing the top news stories across the web
May 30 2014 2:47 PM

Levi’s CEO Says To Never Wash Your Jeans—Is That Sanitary?

1980525-levis-jacket-is-seen-on-display-at-the-new-levi-strauss
No laundering needed.

Photo by Justin Sullivan/Getty Images

This post first appeared on Business Insider.

BI Answers: Does not washing your jeans pose a health risk?

Advertisement

To wash or not to wash? The long-running debate over whether or not to launder your jeans exploded again after Levi's CEO Chip Bergh recommended that people stop washing their denim.

"If you talk to real denim aficionados, they tell you don't wash your blue jeans," Bergh said in a recent interview at Fortune magazine's Brainstorm Green conference.

The unusual advice is something your mother might disapprove of, but microbiologists say there's nothing to worry about—at least from a health perspective.

The argument for not washing your jeans has traditionally been about making your denim last longer. Hot water and detergent can speed up how quickly your jeans fade. Bergh also sees it from an environmental perspective. Not washing your jeans saves water and energy, a message that's part of the company's focus on building sustainability.

But is it safe?

There is no evidence that not washing jeans is hazardous to your health, said Bernhard Redl, an associate professor in the molecular biology department at the University of Innsbruck in Austria. That is, when they are worn under normal conditions, such as everyday street wear.

Bacteria, skin cells, and sweat are transferred to our pants from our own body but "skin microorganisms are generally not hazardous to ourselves," said Rachel McQueen, a professor of human ecology at the University of Alberta in Canada. McQueen's research focuses on the development and retention of odors in textiles.

"There are environments where having sterile clothing is important," McQueen said. That would be true in a hospital, for example, where clothing can transfer infections. "However," she added, "sanitizing your hands is going to be a more important issue here than washing your jeans."

A few years ago, one of McQueen's students wore his jeans for 15 months straight without a single wash and then tested the level of bacteria on them. The student-teacher team was surprised to find that the unwashed jeans carried nearly the same amount of bacteria as those same pants after they had been washed and then worn for another 13 days.

"What I found was just normal skin flora," McQueen told the National Post in 2011. "The counts were really, really similar. The bacteria load from the swabbed areas were pretty much the same."

The Freezing Myth

Although not laundering your jeans doesn't seem to pose any health risks, the smell could become a problem (for you and those around you). Denim-heads have suggested freezing your jeans as a way to kill bacteria and the stench, although there's no scientific proof that this method is effective.

"It is clear that freezing does not kill most of the bacteria," said Redl, "but puts them in a dormant state." Bacteria stops growing in the freezer, but will become active again once you slip your pants back on and those germs are warmed up by the heat of your body.

"I think airing your jeans outdoors in the sunlight would be a more effective method of getting rid of odors and a lot of bacteria," said McQueen.

This post is part of a continuing series that answers all of your "why" questions related to science. Have your own question? Email dspector@businessinsider.com with the subject line "Q&A"; tweet your question to @BI_Science; or post to our Facebook page.

TODAY IN SLATE

Technology

Driving in Circles

The autonomous Google car may never actually happen.

Where Ebola Lives Between Outbreaks

Gunman Killed Inside Canadian Parliament; Soldier Shot at National Monument Dies

Sleater-Kinney Was Once America’s Best Rock Band

Can it be again?

Paul Farmer: Up to 90 Percent of Ebola Patients Should Survive

Is he right?

Science

“I’m Not a Scientist” Is No Excuse

Politicians brag about their ignorance while making ignorant decisions.

Politics

The Right to Run

If you can vote, you should be able to run for public office—any office.

In Praise of 13th Grade: Why a Fifth Year of High School Is a Great Idea 

PowerPoint Is the Worst, and Now It’s the Latest Way to Hack Into Your Computer

  News & Politics
The World
Oct. 22 2014 6:30 PM The Tragedies That Have Shaped Canada's Gun Politics
  Business
Continuously Operating
Oct. 22 2014 2:38 PM Crack Open an Old One A highly unscientific evaluation of Germany’s oldest breweries.
  Life
Gentleman Scholar
Oct. 22 2014 5:54 PM May I Offer to Sharpen My Friends’ Knives? Or would that be rude?
  Double X
The XX Factor
Oct. 22 2014 4:27 PM Three Ways Your Text Messages Change After You Get Married
  Slate Plus
Tv Club
Oct. 22 2014 5:27 PM The Slate Walking Dead Podcast A spoiler-filled discussion of Episodes 1 and 2.
  Arts
Brow Beat
Oct. 22 2014 3:06 PM Writer William Giraldi Wishes Everyone Would Please Stop Likening Him to a Literary Genius
  Technology
Future Tense
Oct. 22 2014 2:59 PM Netizen Report: Twitter Users Under Fire in Mexico, Venezuela, Turkey
  Health & Science
Wild Things
Oct. 22 2014 2:42 PM Orcas, Via Drone, for the First Time Ever
  Sports
Sports Nut
Oct. 20 2014 5:09 PM Keepaway, on Three. Ready—Break! On his record-breaking touchdown pass, Peyton Manning couldn’t even leave the celebration to chance.