The following comments relate to the overheads used for a presentation at the 51st Annual Education Conference of the Florida Environmental Health Association, Inc., May 27, 1999, in Orlando, Florida. In this presentation, I have summarized our current knowledge of the critical control points in hand washing and have recommended solutions to the problem. I have also presented information on our “Safe Hands” program, which a number of large companies are using in the United States. Other companies have been using our nail brush and hand wash method for over fifteen years. These companies have experienced virtually zero foodborne illnesses due to fecal pathogens on fingertips.


1.  Fecal pathogens on fingertips – a major cause of foodborne illnessFingertip washing is the only control with a zero defect potential
1. “When you are sick stay home” is an ineffective government control. People are not doctors who can diagnose their illness. There are other causes for feelings of sickness and diarrhea other than Salmonella typhi, E. coli O157:H7, Shigella spp., Hepatitis A, etc.
2. Pathogens are often shed before there are illness symptoms.


Viral Hepatitis Campylobacter jejuni Listeria monocytogenes
Salmonella typhi Escherichia coli Shigella spp.
Salmonella typhimurium 
and other serotypes
Cryptosporidium spp. Giardia lamblia

3. Pathogens are also shed after people feel well. People can be carriers.


Salmonella typhi Escherichia coli Listeria monocytogenes
Shigella spp. Vibrio cholera Salmonella typhimurium 
and other serotypes
Giardia lamblia

4. When an employee is ill, the supervisor will be aware of it. It is the supervisor’s responsibility to send the employee home.
Conclusion: “When you are sick, stay home” has a high probability of failure for preventing fecal pathogens getting into food and should not be used as a hazard control method.

Explanation:  This overhead points out that the government control stating that when an employee is sick, he or she should stay home, is ineffective and should not be in any food regulation as a control method. Fingertip washing provides for zero defects, as will be pointed out. The principle problem is that before people have any symptoms and know that they are ill with a pathogen, they are shedding pathogens in their fecal material. It is true that when they have vomiting and diarrhea, they shed higher levels. However, we have no idea how much leaks through toilet paper and gets onto fingertips, thus creating a hazard. In addition, after people feel well, they can, and do, become carriers of these pathogens. Again, they will have no symptoms, but if they do not wash their fingertips, they will cause illness. Finally, it has been my experience in talking to supervisors that when a person is ill, those supervisors are well aware of the situation. Therefore, the best strategy is simply to leave the problem to the restaurant owner to solve. People who have taken food safety classes know very well that a major cause of foodborne illness is fecal pathogens on the fingertips. It is up to them to choose the level of risk to which they will expose their customers.



2.  Defenses of skin*
Skin Dryness and acidic conditions (pH 5)Sloughing cells

Resident bacteria

Limit bacterial growth
Remove bacteriaCompete for nutrients and colonization / attachment sites
Hair follicles, sweat glands Lysozyme, toxic lipids Kill bacteria
Sebum from sebaceous glands Protective film on surface of skin Prevents excessive dryness of skin
Beneath skin surface Skin associated lymphoid tissue (SALT) Kill bacteria; sample antigens on skin surface.


  • Salyers, A.A., and Whitt, D.D. 1994. Chapter 1. Host defenses against bacterial pathogens: Defenses of body surfaces. In Bacterial Pathogenesis. American Society of Microbiology Press. Washington, D. C.
  • Prescott, L. M., Harley, J. P., and Klein, D. A. 1996. Microbiology. 3rd edition. Wm. C. Brown. Dubuque, IA.


Explanation:  Today, many companies sell antibacterial solutions and chemicals for the purpose of making hands safe. In fact, this actually leads to damage of the skin, which then leads to less hand washing. This overhead points out the defenses of the skin and their function. It identifies the hair follicles, sweat glands, and other skin defense mechanisms. One must not interfere with these defenses; otherwise, we will have diseases of the skin and less hand washing.



3.  Species isolated from hands of 22 health care personnel*
Category and Species
 No. of Isolates
 Percent of Category
Gram-positive cocci
Staphylococcus epidermidis
Staphylococcus saprophyticus
Staphylococcus capitus
Streptococcus haemolyticus
Alpha streptococci
Staphylococcus aureus
Staphylococcus simulans
Gram-negative bacilli
Klebsiella-Enterobacter sp.
Acinetobacter sp.
Pseudomonas sp.
Proteus-providencia sp.
Candida parasilosis
Rhodotorula rubra
Candida albicans
Candida guilliermondii
Candida glabrata

Adapted from Larson, E., K. J. McGinley, G. L. Grove, J. J. Leyden, and G. H. Talbot. 1986. Physiologic, microbiologic, and seasonal effects of Hand Washing on the skin of health care personnel. Am. J. Infect. Control. 14(2):51-59.

Explanation:  Our studies at HITM have shown that when individuals rinse their hands, 1,000 to 100,000 skin microorganisms are released. This overhead lists some of these organisms and specifically identifies that the only food pathogenic organism on the skin is Staphylococcus aureusStaphylococcus aureus, one of the resident bacteria on the hands, is normally not at a high level and poses no threat until food is abused. In this case, 10 organisms from the skin would have to multiply to 1,000,000–almost 17 multiplications–before this is a problem. Unlike hospital health care workers, there is no need to inactivate the resident S. aureus in the hands of foodservice workers, since time and temperature to prevent spoilage will control the hazard.


4.  Types of hand care*
Hand wash Remove soil and transient microorganisms Soap or detergent and friction for at least 10-15 seconds
Hand antisepsis Remove and/or destroy transient and resident microorganisms to control infection transfer from hands Antimicrobial soap or detergent or alcohol-based hand-rub and friction for at least 10-15 seconds
Surgical hand scrub Remove or destroy transient and resident microorganisms to control / prevent infection in patients undergoing operations Antimicrobial soap or detergent preparation with brush to achieve friction for at least 120 seconds, or alcohol-based preparation for at least 20 seconds

Adapted from: Larson, E.  1995. APIC Guidelines for Infection Control Practice. – APIC guideline for hand washing and hand antisepsis in health care settings. APIC (Association for Professionals in Infection Control and Epidemiology, Inc.).  Washington, D. C.,

Explanation:  There are three basic types of hand care.
1. Hand washing. Removes the soil and transient microorganisms. It can be accomplished in 10 to 15 seconds.
2. Hand antisepsis. Involves some antimicrobial agent. There is a minimum contact time, at least 10 to 15 seconds. Each antimicrobial agent has its own characteristic. Alcohol works quickly, but other agents might take a minute. This means that people who use antimicrobial agents must make sure that they follow the minimal antimicrobial agent contact time. This is unlikely in foodservice without extreme training and enforcement.
3. Surgical hand scrub. Destroys transient and resident microorganisms. This is used to prevent the resident bacteria of the skin getting into the patient’s body during surgery or invasive care. In foodservice, the microorganisms that cause illness are typical transient bacteria from fecal material and have no relationship to the organisms of concern in medical environments.

5.  USDA classification of hand soaps and sanitizers for use in meat processing plants
E1 Compounds:  Hand washing compounds for use in all departments
The compounds must be dispensed from adequate dispensers located a sufficient distance from processing lines to prevent accidental product contamination.
–  After the use of the compounds, the hands must be thoroughly rinsed with potable water.
–  Under conditions of use, there can be no odor or fragrance left on the hands.

E2 Compounds:  Hand washing and sanitizing compounds
–  The compounds must be dispensed from adequate dispensers located a sufficient distance from processing lines to prevent accidental product contamination.
–  The hands need not be washed prior to the use of the compounds.
–  The compounds must always be used at dilutions and according to applicable directions provided on the label.
–  The compounds have been accepted on the basis of their equivalency to 50 parts per million chlorine.

E3 Compounds:  Hand sanitizing compounds (hand dips)
–  The compounds must be dispensed from adequate dispensers located a sufficient distance from processing lines to prevent accidental product contamination.
–  The hands must be washed and thoroughly rinsed prior to the use of the compounds.
–  The compounds may be injected directly into the wash and rinse water.
–  The hands need not be rinsed after the use of the compound.
–  The compounds have been accepted on the basis of their equivalency to 50 parts per million chlorine.
* Gel-based hand sanitizers are limited to use by employees leaving the plant, unless they meet specific guidelines ensuring that residues remaining on the hands will not be inappropriate for food handling.  Only if such guidelines are met can these hand sanitizers be classified as E3.

E4 Compounds:  Hand creams, lotions, and cleaners (including gel-based hand sanitizers not meeting E3 requirements).
–  The use of such compounds is limited to toilets and dressing rooms.  Employees who handle edible products may use the compounds only when leaving the plant.

*  E classifications of hand soaps and sanitizing compounds apply only to USDA-approved processing plants.  Currently, there is no classification system for hand washing products relating to foodservice establishments.

Adapted from:  Miller, M. L., James-Davis, L.A. and Milanesi, L.E.  1994.  A field study evaluating the effectiveness of different hand soaps and sanitizers.  Dairy Food Envir. Sanit..  14(3): 155-160.

Explanation:  The FDA should limit our hand washing compounds to E1 compounds. If we are going to have these ratings, the government must be responsible for establishing the measurement process. E2 and E3 compounds are a problem in the processing industry, because many employees develop reactions to these compounds. They dry the skin and cause skin problems such as dermatitis, especially during the winter. If hands are clean, transient microorganisms are gone, and E2 and E3 compounds serve no purpose. Finally, the E4 compounds (hand creams, lotions) can grow microorganisms if they do not contain antimicrobial agents in them. This can lead to skin reactions. They must be used with care.



6.  Characteristics of selected antiseptic ingredients*
Antiseptic Ingredient
Negative Effect
ethyl (ethanol), n-propyl, and isopropyl
– Antimicrobial (denature proteins)
– Destroy vegetative bacteria, fungi, and viruses
– Emollients, if added, decrease skin drying effect
– Have no effect on spores
– Alcohol pads are less effective than liquid soaps with antiseptic ingredients when used as a brief skin wipe
– Are not good cleaning agents
– Have no persistent effect
– Have drying effect on skin (no more than 70% alcohol / water)
– Are volatile and flammable and must be stored carefully
Chlorhexidine gluconate (CHG)
(cationic bisbiquanide)
– Antimicrobial (disrupts cell membranes and precipitates cell contents)
– Active against bacteria, some viruses (HIV, herpes, flu)
– Good residual effect (up to 6 hr.)
– Not significantly affected by organic
– Available in 2 to 4% concentrations
– May be combined with alcohol
– Activity is pH dependent (5.5 to 7.0)
– Can cause damage if instilled in ears or eyes
– Reports of contact dermatitis, other allergic manifestations, and anaphylaxis in sensitive individuals
(Chloronated bisphenol)
– Disrupts microbial cell walls, precipitates cell proteins, inactivates cell enzymes
– Effective against gram-positive bacteria
– It is persistent
– Not effective against gram-negative bacteria, tubercle bacillus, fungi, or viruses
– Is not fast acting
– Has been shown to produce neurotoxic effects
– General use, banned by FDA. Available by prescription only (3% concentration)
– Should not be used on broken skin or for bathing
Iodine and Iodophores (complex of iodine with polyvinyl-pyrrolidone (povidone) – Antimicrobial (cell wall penetration, oxidation, and substitution of microbial content with free iodine)
– Active against bacteria, viruses, and fungi
– Some activity against bacterial spores
– Neutralized by organic matter
– May cause skin irritation and damage
– Allergic and toxic effects in sensitive persons
(PCMX or chloroxylenol)
– Antimicrobial (cell wall disruption and enzyme inactivation)
– Active against gram positive bacteria, some viruses, and fungi
– Effectiveness increased with the addition of EDTA
– Low incidence of skin sensitivity
– Persistent effect over a few hours
– Minimally affected by organic matter
– Used in a number of hand washing products (0.5 to 3.75% concentration)
– May be less effective than CHG
– Rapidity of activity is intermediate
5-chloro-2-(2,4-dichlorophenoxyl) phenol
– Antimicrobial (cell wall disruption)
– Active against broad spectrum of bacteria
– Appears to be non-allergenic and non-mutagenic (short term), even though it can be absorbed through intact skin
– Has excellent persistent activity
– Activity is minimally affected by organic matter
– Has been tested in concentrations from 0.3% to 4%
– Is commonly used in commercial soaps (1% concentration) to reduce body odor by inhibiting the growth of skin bacteria over time
– Little information about effect on viruses
– Poor fungicide
– Use of this compound in soaps, mouthwashes, toothpastes, fabrics, and plastics may lead to drug resistant bacteria**

* Larson, E. 1995. APIC Guidelines for Infection Control Practice. – APIC guideline for hand washing and hand antisepsis in health care settings. APIC (Association for Professionals in Infection Control and Epidemiology, Inc.) Washington, D. C.
**Heath, R.J., Rubin, J.R., Holland, D.R., Zhang, E., Snow, M.E., and Rock, C.O. 1999. Mechanism of triclosan inhibition of bacterial fatty acid synthesis. J. Biol. Chem. 274 (16): 11110-11114.

Explanation:  These three overheads list the major antiseptic ingredients used in antimicrobial hand soaps. Their negative effects and limited effectiveness against spores and viruses are identified. These ingredients, in some cases, are easily neutralized and will effect the skin. The only universal method that removes the appropriate microorganisms is plain hand washing.

7.  Official test* for hand sanitizers to meet the E2 USDA criterion
1. Grow microbiological cultures to high concentrations (e.g., 108/ml).
2. Make appropriate chemical sanitizer use solutions (e.g., standards for chlorine
are 200, 100, and 50 ppm). The unknown test germicide would be prepared at concentrations expected to be as effective as chlorine.
3. Add 10 mil of 200, 100, and 50 ppm chlorine to 25 x 150 mm medication tubes
and put in a 25° C water bath. Bring to temperature.
4. Starting with the 200 ppm tube, add 0.05 mil of test culture. Shake and return to
the bath. After 1 minute, make a transfer to an appropriate subculture media using
a 4 -mm flamed loop. (The subculture media tube will be used to check for viability.)
5. At 1.5 minutes, add another 0.05 ml of the culture to the 200-ppm solution. Shake
and return to the bath. After an additional 1 minute (2.5 minutes into the test), make
a second subculture. In 30 seconds (3 minutes into the test), add another 0.05 ml. Shake and return to the bath. After 1 minute (4 minutes into the test), make another subculture. Repeat to give 10 total increments. (This requires a total time of 14.5 minutes and 0.5 ml of culture.)
6. Do the same 10-tube test culture destruction test with the test disinfecting solution.
To be considered equivalent in disinfecting activity, the unknown germicide must show the absence of growth in as many consecutive subculture tubes as the chlorine standard.

*AOAC method 955.16 (Aoac, Official Methods of Analysis, 1995.
The test organisms are Salmonella typhi ATCC 6539 and Staphylococcus aureus ATCC 6538.

Explanation:  This overhead points out the method used to verify that a sanitizer meets E2 USDA criteria. It is important to point out that none of the hand sanitizers are required to be tested and validated on hands. This is a laboratory test and has no relationship to in-use effectiveness.


8.  ASTM “glove juice” test method for evaluation of health care personnel handwash formulation1. Test organism = Serratia marcescens ATCC No. 14756
2. Subjects (12) who have not used topical antimicrobials for at least 1 week; no clinical evidence of dermotosis or other skin disorders.
3. Procedure:

  •  Subjects wash hand for 30 seconds wash using plain soap solution.
  • Five (5) ml of Serratia marcescens containing at least 10 microorganisms / ml are dispensed onto the hands, then rubbed over the surfaces of the hands for 45 seconds. The hands are then allowed to air dry for 1 minute.
  • Baseline Recovery A baseline sample is taken after contamination to determine the number of marker organisms surviving on the hands.
  • Wash and Rinse Procedure Five (5) ml or amount specified by the manufacturer of the test formulation is place on hands and rubbed over all surfaces.. After the material is spread, a small amount of water is added from the tap, and the hands are lathered for 30 seconds. The lower third of the forearm is also washed. After completion of the wash, hands and forearms are rinsed under tap water at 40 (± 2° C) for 30 seconds. A total of seven (7) washes with the test formulation are involved. Bacterial samples are taken following the 1st, 3rd, 5th and 7th washes.
  • Bacterial Sampling After specified washes, rubber gloves used for sampling are placed on the right and left hand. 75 ml. of sampling solution** is added to each glove and the glove is secured at the wrist. After the solution is added, the gloved hand is messaged for 1 minute. After messaging, an aeseptic sample of the fluid within the glove is taken.

4. Enumeration of Bacteria in Sampling Solution is performed using standard microbiological techniques.
5. Determination of Reduction. At each sampling interval, changes from baseline counts obtained with test material are determined.
6. Comparison of Test material with a Control Material. If the test material is compared to a control material, an equivalent number of subjects should be assigned to the control product on a random basis. All test parameters will be equivalent for products.
At each sampling interval, changes from baseline counts obtained with test material are compared to changes obtained with control material.

**0.4 g KH2PO4 and 10.1 g Na2hPO4 and 1.0 g isoactylphenooxypolyethoxyethanol in 1 liter of water. Adjust pH to 7.8 with 0.1N HCL or 0.1 N NaOH. Dispense in 75-ml volumes and sterilize for 20 minutes at 121° C

Adapted from: ASTM. 1987. Standard test method for evaluation of heath care personnel hand wash formulation. Designation E 1174 – 87. Annual Book of ASTM Standards. 11.04:779-781.

Explanation:  When in-use effectiveness is measured the glove juice test, as described in this overhead, is used. This is a complex test using a mildly pathogenic organism, Serratia marcescens, and is not applicable to testing the removal of fecal pathogens from fingertips.

9.  HITM procedure for measuring hand sanitation
The feces of healthy people contains 107 to 109 E. coli / g*. E. coli is uncommon in food.

Use E. coli as an indicator of inadequate hand washing after using the toilet.
Utilize Coliform / E. Coli Petrifilmä .

1. Go into the food production facility / kitchen. Pick the 5 employees with the longest, dirtiest fingernails.
2. Take a small separate Ziplock bag for each employee. Add 10 ml of letheen broth to each bag and have each employee rinse their work hand fingertips in the broth in their designated bag. These employees should also use a small toothpick to scrape under their fingernails. This scrapping should also be added to the letheen broth in the Ziplock bag.
3. Plate 1 ml. of the fingertip / letheen broth culture onto Coliform / E. Coli Petrifilmä . Incubate Petrifilmä for 24 hours at 35° C.
4. Significance of results:
   – If < 20 CFU / ml, there is no problem. (Hands have been washed adequately.)
   – If > 20 CFU / ml, there is inadequate fingertip washing.

deWit and Rombouts* found:
   – Before stool samples 4% of kitchen employees, had >20 CFU E. coli / ml on their hands
   – After defecating 25% of the employees had >20 CFU E. coli / ml on their hands.
The average was about 200 CFU E. coli after defecation.

*de Wit, J.C., and Rombouts, F. M. 1992. Faecal bacteria on the hands of carriers: Escherichia coli as model for Salmonella. Zentralbl Hyg. Umweltmed 193(3):230-6.

Explanation:   I have provided a method that we have used in retail food operations to measure the effectiveness of the operation’s hand washing program. The test organism is E. coli, which is already naturally present in the employees’ fecal material. If the employees are properly washing their hands, one would find, perhaps, a low level (<20) E. coli on a few of their hands, as the study revealed. On the other hand, if >20 E. coli were recoverable from fingertips, it was found that the employees were not washing their hands properly after defecating. In the HITM method, we used the Petrifilm&trade; Coliform / E. coli test plate. We put 10 ml letheen broth in a small, plastic, zipper bag in which the employees rinsed the thumb and first and second fingertips. Each employee then used a toothpick to clean the dirt from underneath the fingernails. In addition to being a highly effective measurement process, this is a highly effective way to warn employees that we know how to look for poor or lack of hand washing.

10.  Control of foodborne illness pathogens:  HITM hand washing study
1. 0.1 ml of Serratia marcescens was placed on the thumb and first and second fingers of subjects and allowed to air dry. This was a total of 20,000,000 to 100,000,000 bacteria. To test the number of S. marcescens remaining of the fingertips, the thumb, first and second finger were rubbed together in 10 ml. of letheen broth.
2. Single wash (about 13 seconds): Liquid Ivory hand detergent was put on the hands and fingertips which were washed for 13 seconds under flowing water at 2 gallons per minute. There was a 99.7% reduction.
3. Double wash with fingernail brush (about 20 seconds): A nail brush with about 5 ml. liquid Ivory hand detergent was used on the first wash. Then, the hands were washed again with 5 ml. more of Ivory detergent, without the nailbrush. A total of 99.999% reduction was obtained.
4. The nailbrush was rinsed in 10 ml of phosphate buffer. Compared to the original starting bacterial counts, there was a 99.9998% reduction on the brush.
5. The normal skin bacteria that come off in a wash are about 1,000 to 100,000 per ml of rinse water. It is critical to use a marker organism to show reduction because there is little reduction of skin resident bacteria. The brush becomes contaminated with them.

Explanation:  This overhead summarizes the lab study we did to measure the effectiveness of the nail brush.  We put between 20,000,000 and 100,000,000 Serratia marcescens on fingertips. Using the single wash with Ivory soap, we obtained a 99.7% reduction, which is typical for hand washing. Using the double wash with the nailbrush on the first wash and friction on the second wash, we got a reduction of 99.999%. When we checked the nail brush in 10 ml phosphate buffer, we found that, based on the original starting counts, there were a few S. marcescens remaining, but there was a reduction of 99.9998% on the brush. The samples contained a lot of skin bacteria, which points out that one must use a marker organism to separate out the effectiveness of the hand washing. Relating this to the USDA concept of establishing performance standards, the FDA should set performance standards for hand washing that say that a transient marker organism (e.g., non-pathogenic E. coli) will be reduced by a minimum of 100,000 to 1 in any hand washing process that is to be approved.