Expert Studies Hand Sanitizer's Effect on Alcohol Screenings

Gary Reisfield, MD, an assistant professor in the department of psychiatry with the UF College of Medicine.

Continued use of an alcohol-based hand sanitizer every few minutes could trigger a positive screen for alcohol use in certain types of tests, a University of Florida study confirms. However, UF researchers also discovered a potential biomarker that could allow tests to differentiate between drinking alcohol and exposure to hand sanitizers and other household products, according to Gary Reisfield, MD, an assistant professor in the department of psychiatry with the UF College of Medicine.

The findings, published in the Journal of Analytical Toxicology in March, are particularly significant for people who use hand sanitizers frequently, such as health professionals. For individuals working in these fields who are in substance abuse programs or required to be tested frequently for alcohol use, chronic use of alcohol-based sanitizers could lead to false positives.

Many of the hand sanitizers contain ethyl alcohol, which is the same type of alcohol in alcoholic beverages, says Reisfield, chief of pain management services in the division of addiction medicine. The body does not distinguish between drinking alcohol and handwash alcohol. Anyone out there who is required to abstain from alcohol needs to be very cognizant about alcohol that may be hidden in products such as handwashing gels, mouthwashes, hairsprays and cosmetics, he adds. You need to be careful not just what you put in your body but what you put on your body.

Reisfield adds, Alcohol is a legal drug, so for individuals who are not required to abstain from alcohol, the presence of EtG and EtS in the urine is of no consequence. Impairment is the issue for healthcare workers, individuals operating motor vehicles, etc. Impairment is determined by blood alcohol levels and by proxy breath. It is not determined by urinary biomarkers of past-several-day use.

Although blood and breath tests are more commonly used to detect the presence of alcohol in the bloodstream, they only detect what a person drank recently, Reisfield says. Another type of test, called an EtG, measures the level of substances left behind after alcohol is metabolized and can detect use over a longer period of time. The UF study looked at these types of tests, which measure the levels of ethyl glucuronide and ethyl sulfate in urine as indicators of alcohol use.

The investigators examined 11 subjects with no history of alcohol use, looking to see how frequent use of hand sanitizer affected the levels of these substances in their urine. Study participants used hand sanitizer every five minutes for a 10-hour period for three days in a row, which Reisfield says is similar to what nurses are exposed to while on duty. Their urine was tested at the end of each day and before the start of a new day.

What we found was nearly all the individuals produced alcohol metabolites consistent with drinking alcohol, Reisfield says.

When comparing the levels of ethyl glucuronide and ethyl sulfate in the urine of people who used a lot of sanitizer with people who drank alcohol, the researchers also noticed that the level of ethyl sulfate was much lower in the sanitizer group, not coming close to the cutoffs used to indicate alcohol use.

Reisfield says looking at ethyl sulfate could help laboratories more accurately pinpoint alcohol use. We will be looking at this further in subsequent studies, he says. Ethyl sulfate may be a critical biomarker that has not been looked at in great detail. It may help distinguish between the exposures. We really cannot tolerate false positives. Falsely accusing someone of alcohol abuse can have potentially devastating effects personally and occupationally.

Reisfield says he and his colleagues submitted an additional communication to the Journal of Analytical Toxicology to pre-empt objections that ethanol metabolites in urine might actually result from inhalation of the sanitizer vapor rather than transdermal uptake. We believe that the latter mechanism is the major route of the ethanol absorption that leads to EtG and EtS in urine. In the next phase of our study, we will have non-handwashers in the room among the study subjects in order to prove this point.

Reisfield and his colleagues followed up the original study with a letter to the editor of the Journal of Analytical Toxicology (Respiratory Exposure to Ethanol Vapor During Use of Hand Sanitizers: Is It Significant? Vol. 35, No. 5, June 2011. Pages 319-320) in which they explained, We recently reported urinary ethyl glucuronide (EtG) and ethyl sulfate (EtS) concentrations in subjects intensively exposed to an ethanol-containing hand sanitizer under a controlled research protocol. We concluded that dermal exposure to ethanol can result in urinary EtG concentrations exceeding commonly accepted thresholds for substance abuse recovery programs that require abstinence from ethanol use. In our report, we acknowledged that inhalation of vaporized ethanol during use of the hand sanitizer may contribute to absorption; however, the experiment was not designed to assess the relative contributions of dermal versus respiratory ethanol exposure. An unpublished study by Gregory E. Skipper and colleagues suggested that inhalation was the primary mechanism by which ethanol is absorbed when using ethanol-containing hand sanitizers, and when this study was brought to our attention, we re-evaluated the potential that our study design may have overestimated the exposure to ethanol because of accumulation of ethanol vapor in the study environment.

Reisfield clarifies, The level of transdermal (and respiratory) alcohol uptake, even by liberal users of alcohol-based hand sanitizers poses no known health risks. Glucuronidation is a detoxification mechanism a means of helping the body eliminate drugs. Moreover, only about 1 percent of an alcohol dose is converted to EtG or EtS metabolites. There are some individuals who believe that most of the alcohol uptake from hand sanitizer use results from respiratory uptake. Our group, as you know from our letter, believes that most of the alcohol uptake is transdermal, but there are currently no studies that we are aware of that quantitate the relative contributions of respiratory and transdermal uptake. We believe that it actually doesnt matter much unless a monitored, alcohol-dependent, healthcare worker is cloistered in a closet and exposed to alcohol hand sanitizer all day. But, as I mentioned previously, we will control for respiratory uptake in our next study.

Source: Compiled from the UF Health Science Center news item, Germ-killing sanitizers could have effect on alcohol tests by April Frawley Birdwell, and email interview with Gary Reisfield.