Automatic Handwashing Systems
By Christopher Drummond
Modern healthcare has long struggled with problems related to handwashing. The FDA says that 80 million cases of food poisoning occur in the United States each year and associated costs are estimated to be between $7.6 and $23 billion annually. Additionally, over 70% of all outbreaks originate in food service operations and as many as 40% are the result of poor handwashing.
Growth in Hospital-Acquired Infections
According to the CDC, the hospital- acquired infection rate is increasing. The CDC estimates these infections contribute to at least 80,000 patient deaths each year, and approximately 5 to 10 % of patients annually contract infections while in the hospital. Nosocomial infections kill more Americans every year than traffic accidents.
According to a recent article in AJIC, handwashing is the single most important procedure in the prevention of nosocomial infections. According to the CDC, half of the infections that are acquired in hospitals could be prevented by effective handwashing. A 1994 study published in AJIC studying glove use and handwashing practices in a hospital concluded that although policies and precautions have been implemented to enforce proper handwashing practices, staff members washed hands after only 32% of high-level (exposure to body fluids) contacts, and that proper handwashing only occurred 12% of the time. In addition, the level of compliance varied significantly among different units in the same hospital. This suggests that handwashing and glove use are not practiced with blood and body fluid contact despite education in precautions and written infection control policies.
Compliance with handwashing has historically been poor. When surveyed, hospital staff members overestimate the frequency with which they wash their hands, as well as the duration of handwashing. Increasingly hectic schedules, the inconvenient placement of sinks, and lack of education about proper handwashing account for lack of compliance. To encourage increased compliance, more innovative feedback and educational endeavors are needed as well as ways to make the handwashing process easier and faster.
Data collected over five years from an intensive care unit showed that the hospital-acquired infection rate decreased almost 60% when an education and enforcement program for handwashing was implemented. The rate of infection then slowly increased over the next four years, until another program was instituted, when it was again gradually reduced. The rise in infection rate was attributed directly to handwashing practices, and indirectly to personnel turnover (AJIC). Many healthcare professionals wash only the palms and backs of their hands, whereas the main contact points are the fingers and fingertips. Where no control for agent, duration, or technique exist, the institution of standardized handwashing technique alone results in a decrease in infection rates (AJIC).
Use of Automatic Handwashers
In 1983, an OB/GYN physician and an owner of car-washing facilities created automatic handwashing systems for use in healthcare. Consequently, they created a company called Meritech, Inc. to facilitate this idea. By 1989, after six years of effort, the company developed the first prototype of an automatic handwashing system. Approximately 18 hospitals adopted this technology immediately. However, the systems were large, expensive ($11,000), and unreliable. In the early 1990s the technology improved and became known as CleanTech automatic hand and glove washing systems. In the mid-1990s Meritech developed the CleanTech 2000S system--smaller, more cost effective, and more reliable. Then in 1999, Meritech introduced the CleanTech 400. The CleanTech 400 serves as a sink in addition to handwasher. In the early 1990s, many markets including healthcare, food processing, produce, supermarkets, food service, cleanrooms, and daycare facilities began using the benefits of these systems.
CleanTech automatic handwashing systems are designed to remove microorganisms, bacteria, pathogens, and particles from hands and gloves without hand-to-hand contact. Users simply insert their hands into two open cylindrical chambers. As the hands enter, an optical sensor initiates the cycle; the cylinders begin rotating and hidden nozzles (20 in each cylinder) automatically spray a water and antibacterial solution combination on the hands and under the fingernails. The automated handwasher then rinses with non-irritating, high-pressure sprays of water. Hands or gloves are then dried with paper towels, air-dryers, or with a dryer incorporated into the system.
This automatic handwashing system performs the wash and increases handwashing compliance up to five times that of manual handwashing methods.
Automatic handwashing has gained popularity in many industries: hospitals, doctor's offices, dental offices, clinics, retirement facilities, assisted living facilities, daycare facilities, pharmaceutical clean rooms, dairy, beef, poultry, and more. There are many common and specific reasons for each type of industry to use automatic handwashers.
Image is the most common reason for the popularity of automatic handwashing. Many automatic handwashing customers invested in the advanced technology because it was popular with their customers. Whether the customers are patients, consumers or business customers, owning state of the art handwashing technology demonstrates that a company is committed to safety.
Especially in healthcare, handwashing compliance is important. Automatic handwashing significantly increases employee handwashing. Employees use the automatic handwasher because it is gentler on the hands. No training is required--employees simply put their hands in the handwasher. Because an automatic handwasher controls the water, temperature, soap dispensing, the on- and off-function, and the system cleaning, it is convenient to use.
The Science and Efficacy of Automated Handwashing
The concept behind automatic handwashing is to remove the significant variability in effectiveness of a manual handwash. The technique used to wash hands manually varies from one person to the next. Further, there is variability in how well the person cleans under the fingernails, between the fingers, on the backs of the hands and around the wrists. Manual handwashing can be as effective as automatic handwashing if the wash process is done correctly; however, it is much less effective when done poorly. By automating the wash process this variability is minimized. The design of the CleanTech system ensures consistent water pressure, water temperature, soap usage, cycle length and skin coverage. This allows consistent bacteria reduction from one pair of hands to the next. The activity of the wash cycle via an infrared sensor allows no-touch operation and prevents cross contamination. The system also washes each hand individually, eliminating the hand-to-hand contact used in a manual handwash. Laboratory studies have shown a consistent bacteria reduction of between 99 and 99.9%.
In some field applications of the automatic handwashing system, the system is used to remove bacteria from a gloved hand rather than a bare hand. Testing has shown that these systems effectively remove organisms from gloves as well as hands. One of the driving forces behind the creation of automated handwashing was the variability of manual handwashing. To quantify this variability, testing was conducted to define a typical manual handwash and measure the standard deviation from one wash to the next. This data was then compared to the results from an automated handwash. This study showed that automated handwashes are significantly more consistent in bacteria reduction than manual handwashing.
Many automatic handwashing users report that employees are three to four times more likely to wash their hands when an automatic handwasher is used. Some customers went so far as to conduct studies on employee handwashing compliance rates with automatic handwashing versus manual handwashing. People tend to use the automatic system much more than a manual handwash sink because they enjoy the sensation of washing in the automatic system.
Compliance is defined as the ratio of the number of times a handwash is performed over the number of times handwashing is required by protocol. Compliance rates of 100% are very rare and usually only occur when the wash process is either monitored by a supervisor or when employees not complying with the handwashing protocols are refused entry into the facility. This monitoring intensive system is usually implemented only in critical manufacturing processes such as semiconductor cleanrooms, where the cost of product contamination can run into the millions of dollars from a single incident. Most other facilities have a less than perfect compliance rate (30 to 60% is typical).
The automatic handwashing system has a compliance monitoring system that counts the number of hand washes occurring in the machine. This allows the supervisor to measure whether employees are washing their hands as frequently as required. With this option, the supervisor has the ability to reset the counter periodically, e.g., every shift. This provides information on employee handwashing on a real-time basis. An individual compliance-monitoring system is also available with this system. In one automatic handwashing system, each employee enters his or her number on an attached keypad. The supervisor can then print a report describing each employee's frequency, duration and time of handwashing every shift.
CleanTech washers have been tested by Underwriters Laboratory for compliance with UL544 criteria and have been determined to meet these requirements and are UL listed. This listing means that the mechanical and electrical systems in the unit have been tested safely. The National Sanitation Foundation (NSF) has examined the same units and has given NSF approval under category C2. This approval means that the units are constructed in a manner that is sanitary, easily cleaned and safe to operate around food.
For many years, the USDA was also in charge of approving the chemicals used in the system. The chemicals were tested for minimum performance and then categorized into various applications such as hard surface disinfecting, handwashing, or hand sanitizing. With the implementation of the HACCP program by the USDA, the role of the agency has changed dramatically in respect to the relationship with the manufacturer. Rather than the old method of having an inspector walk the plant and look for conditions which violated USDA regulations, the manufacturer now defines their own regulations and standard sanitation operating procedures which are approved by the USDA. The HACCP program then requires the company to police themselves by monitoring the defined critical control points to ensure compliance and record the data for review by the inspector in charge. Consequently, the USDA does not approve either equipment or chemicals for use in inspected plants; rather, the user is responsible for specifying the equipment or chemicals which meet their own requirements, as outlined in the HACCP program. Because of the compliance monitoring systems, automatic handwashers are complimentary to any HACCP program.
Automatic handwashing systems are available in several different models. Some have a plastic housing and others are constructed of all stainless steel. All of the CleanTech units have the same basic components and operate similarly.
The unit is activated when the infrared photoeye beam (invisible to the human eye) is broken by the placement of the hands into the two round cylinders. The unit then begins a preprogrammed cycle consisting of a period of time in the beginning of the cycle during which antimicrobial solution is mixed with water and dispensed onto the hands. Next, only water is dispensed onto the hands to rinse the soap off. Typically, the total cycle length is about 12 seconds, three of which is the soap and the water mixture.
The rotating cylinder assembly consists of an inner and outer cylinder made from ABS plastic. The inner cylinder is slightly smaller in diameter than the outer which allows the two parts to nest together. Water enters the cylinder assembly through the inlet located at the closed end of the outer cylinder. The water fills the space between the inner and outer cylinder until it reaches the o-ring seal between the two at the open end. At this point the only place for the water to go is out through the series of 20 nozzles installed throughout the wall of the inner cylinder. These nozzles are arranged in a helical pattern so that as the assembly rotates clockwise, the helical pattern will wash debris from the wrist area down off the end of the fingertips. There are also four nozzles located in the bottom of the inner cylinder that direct water spray under the fingernails, an area which is often missed in manual washing.
Water temperature, motor speed, soap draw and cycle length are all adjustable through a potentiometer on the printed circuit board within the electronics module.
In one version, the hand drying option will dispense heated, compressed air onto the hands after the completion of the wash cycle. The operator moves their hands in the air stream that dries the hands through a combination of mechanical air removal and evaporation. The dry cycle takes between 40 and 60 seconds.
Chemical Washing Solutions
A variety of solutions have been tested for efficacy and compatibility with the automatic handwash systems. These include: Chlorohexidine Gluconate in 4% concentration (CHG 4%), Chlorohexidine Gluconate in 2% concentration (CHG E-2), Quat E-2, Quat E-3 and A-1 Self-Clean. The first three chemicals listed are used for handwashing, the Quat E-3 is used for hand sanitizing and the A-1 Self-Clean is used for hard surface disinfecting.
The plumbing tree in CleanTech systems is incompatible with chlorine-based solutions. The highest volume soap used, the CHG E-2, has been found to be most effective in reducing transient and resident bacteria.
Alcohol-based waterless gels that are simply rubbed into the hands and allowed to evaporate are not a substitute for handwashing. Several different varieties of no-touch handwashing units are available which range from simple no-touch faucet-activated sinks to systems that will dispense water, soap, and warm air for drying, all using a no-touch design. These systems represent an improvement over the traditional hand-activated units because they can prevent cross contamination from one user to the next. They do, however, require a manual handwash; therefore, the variability from one wash to the next is still an issue. Gloves--thought by some to be the ultimate protection for consumers from food-born illness--have some significant problems according to recent studies. The rate of bacterial growth under a glove may be higher than on a bare hand. This would not be a problem if the gloves were an impenetrable barrier between hand and the product being touched by the gloved hand, but this is not the case. Gloves may have defects, allowing the transmission of bacteria from the hand to the product. In many cases, the glove provides a false sense of security so that employees are less likely to wash their hands.
Automatic handwashing offers standardized procedure, increased compliance, and increased efficacy over typical manual handwashing. Because of these benefits and the fact that it pays for itself in a short time, automatic handwashing is fast becoming the standard in many healthcare applications.
Christopher Drummond is the President and CEO of Meritech, Inc. The design engineer responsible for designing the hanwasher is Christopher Maybach. Meritech was formed more than 10 years ago and focuses on automatic handwashers.