Plastic surgeons rely on their hands for a living, but not all of them are clear on how to best keep those hands clean, a small study suggests.

In a Web-based survey of 122 U.S. facial plastic surgeons, researchers found that only half — 53 percent — knew that alcohol-based rubs are considered the best agent for killing bacteria on hands that appear unsoiled.

They fared better when it came to the best management of visibly dirty hands. In such cases, soap and water is the cleansing method of choice — something that three-quarters of the surveyed plastic surgeons knew.

Far fewer, however, could correctly identify all the situations in which they should clean their hands. Only 42 percent said they should do so before and after contact with a patient, and before and after using examination gloves.

Dr. Douglas D. Leventhal and colleagues at Thomas Jefferson University Hospital report their findings in the Archives of Facial Plastic Surgery.

Hand-washing practices have come under scrutiny recently, as they are the most effective way to prevent the spread of potentially deadly infections in the hospital. The U.S. Centers for Disease Control and Prevention and the Joint Commission, which evaluates and certifies hospitals and other health care organizations, have made hand-washing a priority in their guidelines.

Plastic surgeons are not alone in their lack of hand-washing know-how. Studies have shown that healthcare workers' adherence to hand-hygiene guidelines is generally "abysmal," Leventhal and his colleagues write.

Lack of awareness is one reason, but past research suggests there are numerous other barriers, like heavy workloads, shortage of sinks and skin irritation from the cleansing products.

That means that while education is an important first step in improving healthcare workers' hand hygiene, other steps should be taken as well, according to Leventhal's team.

Hospitals, the researchers note, should give workers written guidelines, provide enough easily accessible cleansing products, and monitor employees' compliance with hand-washing rules.