It’s not necessarily big news that 63 percent of Americans have had what is euphemistically described as a “particularly unpleasant experience in a public restroom” due to unsanitary facilities. What’s scary is that this number is on the rise—up from 51 percent last year—and researchers have begun to quantify the negative effects these experiences have on businesses such as restaurants.

These numbers come from the latest edition of an annual hand washing survey conducted by commercial restroom equipment manufacturer Bradley Corp. As in previous years, a strong majority of survey respondents affixed the blame for gross-out conditions on businesses owners, rather than on members of the public whose unsavory restroom habits create problems in the first place. You own the restroom, it’s your problem, consumers seem to say.

Specifically, 73 percent of survey subjects told Bradley’s survey-takers that a bad restroom indicates poor management. Two-thirds say an unsavory restroom lowers their opinion of a company, shows the business doesn’t care about customers and gives the impression the company is lazy or sloppy. Worst of all, 64 percent of respondents said they would either think twice about patronizing the business or would not go there again. Bad news for an industry like restaurants where creating repeat customers is the name of the game.

“In our fifth year of doing this national survey, it remains clear that the cleanliness of the public restroom is very important to customers, employees and other stakeholders who engage with a your business,” says Jon Dommisse, director of global marketing and strategic development for Bradley.

The survey also quizzed respondents about their personal hand washing habits and how they perceive the hand washing habits of others. Restaurants came in for special mention in this category, and not in a good way.

“As for restaurants in particular, Americans say they have the highest level of germ concerns tied to hand washing—or lack thereof,” the survey found. “In fact, the majority—76 percent—of Americans are most concerned about somebody not washing their hands in restaurants, followed by hospitals/clinics/doctors/dentists offices (65 percent).” Which is to say, consumers told Bradley they hold restaurants to a higher standard of cleanliness than hospitals and other healthcare providers.

Restaurant operators can’t do much about how customers behave in their restrooms. The best you can do is to make sure staffers make frequent checks and perform spot cleanups when conditions merit. But you can continue to preach the importance of hand washing to your team.

When you do, be aware that women have better hand washing habits than men, according to Bradley’s results.

The survey found that 74 percent of women always wash their hands after using a public restroom, but only 60 percent of men do. Non-hand-washing women said they used hand sanitizer instead. Men said they skipped washing because of a lack of soap, because of the unclean condition of a sink or washbasin, or because they had used a hand sanitizer. Men were much more likely to refrain from washing up because they said they “didn’t feel the need.” Whoa.

So when discussing food safety and hand washing procedures with your staff, give special attention to your male employees. “Men need to get the memo that hand washing is important no matter what,” Dommisse says. “You just can’t argue with the research that says it is the number one way to prevent illness and stay healthy.”