When sanitizing hands, 3 ml is recommended in order to achieve a rubbing time of 30 seconds. While this knowledge may be common in healthcare settings, healthcare workers often fail to meet this target. By adhering to hand hygiene recommendations, healthcare workers can provide safer patient care.
Thorough hand hygiene is considered the easiest and most cost-effective, measure to prevent nosocomial infections. It is firmly established in everyday hospital routine, implemented by healthcare workers (HCW) according to guidelines based on the five moments of hand hygiene.
In the wake of the current COVID-19 pandemic, practicing thorough hand hygiene is becoming even more important – in the medical sector and beyond. With the rapid upsurge in sanitizer usage, countries around the world are experiencing bottlenecks in supply. In many cases, this has forced hospitals to meet their own demand by producing alcohol-based preparations in-house. As we strive to meet the current demands for sanitizer, it is critical that hand hygiene is carried out at the right time and in the right way.
Hand disinfection with limited virucidal agents sufficient for combatting COVID-19
To support infection prevention and control within the current climate, it is important hand disinfectants are effective against the usual hospital germs, as well as the novel coronavirus (SARS-CoV-2). In this case, alcohol-based hand rubs with a “limited virucidal” spectrum of activity – agents that are effective against enveloped viruses – provide sufficient protection against the coronavirus.
“The withdrawal quantity of 3 ml disinfectant for every hygienic hand disinfection, in combination with the recommended rub-in time and the correct rub-in technique, ensures the required reduction of germs on the hands. In addition, it must be ensured that a hand disinfectant is used which also has the required spectrum of efficacy.”Andreas Glöckner, M.D., Medical Director
Solutions that reliably inactivate the novel coronavirus are those the nomenclature “limited virucidal” and “virucidal” agents. In addition to the enveloped viruses, these products are also effective against more persistent, non-enveloped viruses.
3 ml over 30 seconds, per hand disinfection recommended
From a scientific perspective, 3 ml is considered an important dosing threshold where we can achieve a standard of 5 log10 reduction in germs. Leading institutions, such as the World Health Organization (WHO), and the Commission for Hospital Hygiene and Infection Prevention at the Robert Koch Institute (KRINKO), recommend a dosage of 3 ml of sanitizer for hygienic hand disinfection. This dosage quantity is also officially defined in the European Standard EN 1500.
A number of studies point to the efficacy of a sufficient dose of disinfectant on the hands. A comprehensive study by Prof. Günter Kampf and colleagues clearly established that a lower volume of disinfectant is associated with less germ reduction, resulting from the fact that the hands of hospital staff were not sufficiently covered by the sanitizer at lower dosage quantities. Disinfection with a dosage of less than 2 ml resulted in so-called wetting gaps of over 60 percent.  Therefore, the 3 ml dosage is considered to be an important value in ensuring quality hand hygiene.
The German National Reference Centre for Surveillance of Nosocomial Infections (NRZ) uses the value of 3 ml to determine a total number of hand disinfections carried out on the basis of reported ward or hospital-wide consumption data.
The rub-in time is another factor that affects the quality of the hand hygiene event. Here too, EN 1500 specifies a standardized procedure comprising six steps, each taking five seconds in duration. These steps take 30 seconds per hygienic hand disinfection.
Hygiene professionals regularly train doctors and other healthcare workers in these two aspects of hygienic hand disinfection, and recommend taking two full strokes from Euro dispensers. This corresponds approximately to the required 3 ml dosing quantity.
The truth about hand hygiene quality
In practice, however, the situation is often different. Healthcare workers might take two strokes of disinfectant from a dispenser, but incomplete strokes. In these instances, it is then unclear how much disinfectant has been dispensed. Other healthcare workers might take just a single stroke from the dispenser, which inevitably results in the hands not being completely wetted.
In addition, adjustable dosing pumps may be set on a lower dosing volume – 1 ml for example. In this instance, even the two full strokes would not necessarily be sufficient to comply with the recommendations.
A study by Prof. Simone Scheithauer underlines the need to pay special attention to volume dispensed during each hand hygiene event in hospitals. The reason is that without targeted training an insufficient average of 1.69 ml is typically dispensed each time hands are sanitized.
This failure to comply with recommendations endangers patient safety, which is especially disconcerting during pandemics, such as COVID-19.
Green light for infection prevention
Implementing technology, such as the ingo-man® SmartNose can actively improve the quality of hand hygiene practiced in healthcare facilities in a simple way. This retrofittable, intelligent module provides instant, visual feedback to healthcare workers.
A green feedback LED on the top of the module lights up when a sufficient volume of disinfectant has been dispensed. The effects of instant feedback have been well studied, and are believed to promote better hygiene compliance. [2,3]
Installed in the blink of an eye
The ingo-man® SmartNose is compatible with all manual Euro dispensers of the ingo-man® plus series and can be easily installed as a retrofit unit on the devices. The fact that the dispenser accepts all sorts of bottles from different disinfectant manufacturers means that hospitals have flexibility to switch between suppliers of filling goods. This flexibility is crucial in maintaining a secure supply, avoiding shortages or bottlenecks in supply, especially relevant during pandemics.
Thanks to the connection to the OPHARDT Hygiene Monitoring System®, which can be made at any time, hygiene specialists can monitor hand hygiene compliance and provide targeted training to staff based on data collected from the intelligent dispenser systems.
We would like to emphasize that with the technical progress in the area of disinfectant dispensers, we are gradually coming closer to optimum hand hygiene quality. Even though there is currently a controversial discussion about the extent to which the duration of 30 seconds for hygienic hand disinfection is necessary, a sufficient withdrawal quantity of at least 3 ml remains the gold standard everyone should strive for.
 Kampf G et al. Less and less–influence of volume on hand coverage and bactericidal efficacy in hand disinfection. BMC infectious diseases. 2013;13: 472.
 Scheithauer S et al. Do WiFi-based hand hygiene dispenser systems increase hand hygiene Compliance? Am J Infect Control. 2018;46:1192-1194
 Diefenbacher S et al. A quasi-randomized controlled before-after study using performance feedback and goal setting as elements of hand hygiene promotion. J Hosp Infect. 2019;101:399-407