Forty years ago this month I started as a sanitarian with the New Jersey State Department of Health Department. My mentor was Ray Chapman, a consummate professional who worked in urban settings since he left the Navy after WWII. We had the equivalent of the Public Health Service 1962 Food Service Sanitation (FSS) Manual, which was a far cry from today’s Food Code. The FSS manual, however, provided us with enough guidance that we were able to do a credible job in protecting the public’s health. According to Ray, the trick to using such a standard was more about observation and understanding the operations within the retail food establishment and how they relate to food contamination, rather than citing every roach, mouse dropping or floor stain (the good old walls, floors and ceiling model).
Looking back, I marvel at his foresight in emphasizing improper holding temperatures, inadequate cooking, contaminated equipment, food from unsafe sources and poor personal hygiene in his inspections. That lesson has been with me all these years, and I think that I have been moderately successful in following his example.
Observation of activities in food preparation has been and will continue to be the primary tool in my consultation and enforcement activities. The more I observe, apart from improper (or complete lack of) hand washing, the more I have come to realize that the most significant independent variables that can possibly pose the greatest risk of disease spread through cross-contamination are cutting boards, wipe rags and countertops—the first two being the primary sources of microbial cross-contamination. I cannot recall any time I’ve spent in a kitchen where either cutting boards or wipe rags posed a zero risk. If controls in commercial establishments are varied and not exactly circumspect, I shudder to think what they are like in consumers’ kitchens. What we do at home, generally translates into what we do at the workplace. In a 1992 study, only 54% of consumers said they would wash a cutting board with soap and water after chopping fresh meat and before cutting fresh vegetables for a salad; the rag used for washing that 54% is another issue altogether.
While the Food Code does a credible job addressing these issues, like all things, expediency will out and old habits are hard to break. The relevance of cutting boards and wipe rags are oftentimes overlooked because of their commonality and reliance on evaluating their condition rather than use.
A Cut Above
To set the stage on the enforcement issue of cutting boards used in retail food establishments, consider that the U.S. Department of Agriculture (USDA) had no scientific evidence to support their recommendation that plastic, rather than wooden cutting boards be used. Whereas the Food Code permits the use of cutting boards made of maple or similar close-grained hardwood, it also calls for “non-absorbent” and easily cleaned materials for surfaces that food contacts. Neither agency prohibits commercial establishments from using wooden cutting boards, nor do they specifically authorize acceptable plastic materials, or specify how plastic surfaces must be maintained. At best, this is a regulatory conundrum.
Needless to say in preparation for this article, I was unsure about current thinking within the regulatory community. So, I asked several seasoned sanitarians attending the recent National Environmental Health Association’s (NEHA) Annual Educational Conference about their interpretations of cutting board regulations. Everyone seemed to have a different “take” on enforcement. Opinions ranged from disliking wood in favor of composite materials to disliking composite blocks in favor of wood, and no one really agreed on a single criterion on when blocks, regardless of type, should be refurbished or replaced. On the plus side, however, there was no argument on cleaning and sanitizing methods and frequency of continuous-use cutting blocks and boards; everyone agreed to the four-hour rule, or when the boards are used with different foods.
The selection of cutting boards varies widely. The usual materials are close-grained hardwoods and plastic. Although boards made of bamboo, marble, glass, or pyroceramic materials are available and found in the retail community, but at a lesser frequency. While wooden cutting boards have been used for centuries; those made from various polymers have only been available since the early 1970s, but they did manage to change the face of the industry.
The argument over which type is better was dispelled by researchers who demonstrated that when bacteria were inoculated on both wooden and polymer boards, bacterial recoveries from wooden boards generally were less than those from plastic boards, regardless of new or used status and found no differences between wood types (basswood, birch, maple, maple or walnut). Additionally, usual cleaning with hot water and detergents was found to be effective in removing bacteria, regardless of the species, wood type, or whether the wood was new or used.
On the other hand, more recent studies by the U.S. Food and Drug Administration (FDA) has confirmed the conventional belief that plastic is safer than wood for cutting meat and poultry. One study reported that new wooden boards had antimicrobial qualities while plastic cutting boards trapped bacteria. Another study found that microorganisms became trapped in wood surfaces and were difficult to dislodge by rinsing. Once trapped, these bacteria survived in a dormant stage and could recontaminate the surface when conditions were again favorable, potentially causing foodborne illness. On the other hand, the study found that microorganisms were easily washed off plastic surfaces. So, the argument is nowhere close to conclusion.
With that in mind, and with the opinions of other experts and my observations, I’d like to offer some general guidelines on the proper use of cutting boards, starting with the selection of replacing old ones:
• Choose boards with a smooth, hard surface and rounded corners that will not chip or crack. The boards should not be so hard as to harm or dull knives, yet they should be dense enough to resist slice marks that can harbor bacteria.
• Preferably, cutting boards should be nonporous. This would include boards made of plastic and pyroceramic materials; the latter can be refurbished. However, boards made of hardwoods, although somewhat porous, are perfectly acceptable provided that they meet the other criteria. Wooden cutting blocks come in two types. The end-grain type (butcher block) is more durable than flat-grain boards which are easier to manufacture and are considerably less expensive. With the end-grain type, the wood is aligned up and down. When the knife strikes the surface during cutting, the grain of the wood actually separates and then closes when the knife is removed. This accounts for the self-healing aspect of the end-grain surface. The wood itself is not cut, but instead the cuts are made between the fibers and knife marks on this type of board are not as visible.
• Cutting boards should be easily cleanable. The cutting board’s surface should allow effective removal of soil by normal cleaning methods. In addition, there should be little likelihood of the surface’s role in introducing pathogenic or toxigenic agents or other contaminants into food when used for its intended purpose.
• Select only cutting boards that are nontoxic and approved for contact with food. It is absolutely essential to select commercial cutting boards that are listed under ANSI/NSF Standard 51 listed materials.
• All plastic and wooden cutting boards wear out over time. Replace cutting boards that become deeply scratched, carved or grooved. Boards that are scored, gouged and chipped are no longer cleanable and therefore cannot be effectively cleaned and sanitized. As a rule of thumb, a cutting board should be replaced (or refurbished if practical) when a dampened cotton swab is lightly rubbed over the surface and its fibers become dislodged and adhere to the board. A more subjective, but equally valid criterion is to replace cutting boards when they become permanently stained through use and feel rough to the touch. While neither criteria is scientifically valid or has been tested against the potential for microbial cross-contamination, they do indicate a condition that lies somewhere between a cleanable and acceptable surface and one that can support the growth of mushrooms and lichens. The old saying “when in doubt, throw it out” certainly holds true for cutting boards.
When using, cleaning and sanitizing cutting boards, the following practices will markedly improve food safety in the kitchen or on the prep table:
• Do not cut or chop anything on a cutting board such as salad, vegetables or other ready-to-eat (RTE) foods that has been used to trim raw meat, poultry or seafood without first washing and sanitizing the board.
• If possible, always use a clean, separate, color-coded cutting board for fresh vegetables, fruits, breads and other food that will not be cooked prior to eating. To avoid cross-contamination and for safety’s sake, boards used for raw meats, poultry and fish should also be uniquely color coded. The color codes should be readily recognizable so that the boards are not comingled or used for an unintended purpose.
• When cleaning soiled cutting boards, scrape off any food that is stuck to the surface and scrub all cutting boards completely with hot water and detergent after each use and sanitize as appropriate. Use white pads to remove stubborn food materials; do not use stainless steel pads or wire brushes because they will damage the finish. Dishwashers are usually very good cleaners for most cutting boards but may damage thin plastic or wooden boards. Wooden boards should not be placed in dishwashers before reading the label or checking with manufacturers to see whether they can be.
• Clean and sanitize cutting boards from time to time. Best practice is to clean and sanitize boards within four hours (when used with the same food) using a mixture of one teaspoon of chlorine bleach to one quart of water (1 tbsp/gal) or an approved sanitizing solution that is mixed in accordance with manufacturer’s instructions. After cleaning, flood the board with the sanitizer and let it stand 10 minutes. Then, rinse completely with fresh water.
• Let cutting boards dry completely; do not stack together or with other kitchen gear so that they remain wet. Store cutting boards so that they remain clean, dry and in such a manner to prevent any contact that could potentially recontaminate food contact surfaces.
Before I leave the topic of cutting boards, I would like to single out wooden cutting boards and mention “seasoning” to prevent staining and absorption of food odors and bacteria. The manufacturers typically recommend that proper surface treatment is important to guard against germs and/or mold growth on both new and older boards. The wood surface needs an oil treatment that can be repeatedly applied to fill the wood pores and repel food particles, liquids and other fats and oils. Most manufacturers of wooden cutting blocks recommend the regular use of USP-grade mineral oil. This is both an inexpensive and pure food-grade oil that will not turn rancid as vegetable oils. Mineral oil remains safe throughout its life. The words “food safe finish” in a description of a wood product generally means mineral oil has been used. Simply wipe mineral oil on the surface of the board and let it soak in. Any excess can be removed with a clean dry cloth—which of course, brings me to the next topic.
Sponges and rags are ideal environments for disease-causing microbes. In particular, the continually moist cellulose sponge provides multiple surfaces for germs to adhere, a steady supply of nutrients through the trapped minute food particles, and continuous moisture. Even when the sponge dries out, bacteria can survive for several days as it slowly dries. The kitchen sponge embodied all we’ve learned about the biology of microbes (FATTOM). So at long last, we have replaced the sponge with the safer and more sanitary wipe rag. In spite of this progress toward the protection against cross-contamination, the regulatory community is not in total agreement when it comes to implementation. It was another question I asked of the seasoned veteran sanitarians.
The answers I received on the enforcement of the proper use of wipe rags and wipe rag sanitation were rather curious. We wonder about the risk of cross-contamination by these bedeviled pieces of cloth and design programs to eliminate microbial colonization and spread. Yet we continually find rags covered in food, grease and grime sitting on food contact surfaces, counters and every conceivable area in a bar operation. We observe cooks and other kitchen staff continually wiping their hands on the soiled rags which are attached to their aprons and wait staff continually using the same rag for a myriad of chores.
To reduce the risk of cross-contamination we routinely expect the establishments that we inspect to provide sanitizer solution buckets throughout the kitchen and at all wait stations. We expect to see wipe rags when not in use, are kept in these sanitizer/water solution buckets. We know that if the wipe rag program is properly implemented the sanitizer can kill off any bacteria that may be present on a soiled rag, and that the surfaces on which the rag is used are left relatively microbe-free. Then we sit and observe.
The rags in the sanitizer buckets remain there. The solution sees barely a ripple the entire time. The sanitizer titer is proper and the solution is clean. If, on a joyous occasion, the rags are used, the one using the rag will return it to the bucket and promptly wipe their hands on the soiled rag attached to their apron. Even though wipe rags still abound in the kitchens and wait stations, those kept in the solution determine the level of compliance and consequently meet the code. One great truth becomes quite obvious: Not many kitchen workers or wait staff enjoy placing their hands in a too-small, room-temperature bucket o’bleach to wring out a rag and use it to wipe up little messes and then return it to the too-small bucket and rinse it out. Unless the culture of the establishment is such that it forces compliance that rag bucket will see little use and cross-contamination from less-than-savory rags will remain an issue.
As with cutting boards, commercial wipe rags come in many types including single-use, multiple-use and discard, and, re-use with reprocessing. The first two types are ideal; no muss, no fuss, but they are pricey and constitute a sizeable waste stream. Of course, the wipe rags that are designed for reuse include that soiled rag or towel that is attached to the apron. This means, that regardless of the type, rags need to be readily available and need to come with some operating instructions. The former is quite doable, but the latter is more difficult to achieve. I’ve sat and listened to numerous vendors tell me about the marvels of their wipe rags and the accompanying wipe rag sanitation programs. I am absolutely convinced that the success of these initiatives is directly proportional to their cost. So for these reasons, I would like to offer something a bit more practical for consideration:
• Wipe rags come in two basic types: the less expensive natural fibers such as cotton, and the more expensive synthetic microfibers. With proper care, each can be reused at least eight to 12 or more times. The microfiber cloths are generally designed for specific uses and include those that are ideal as all-purpose towels and super-absorbent cleaning cloths. I’ve convinced several of my clients to provide their staffs with many wipe rags, placed at numerous locations throughout the facility, during a shift for use one or two times and then disposed for reprocessing. With enough wipe rags available, cleaning can be done properly and cross-contamination from either rag or surface can be avoided altogether.
• Consider laundering of soiled wipe rags versus contract laundry services. In several operations where we changed the wipe rag policies, whenever practical, we installed either a 50- or 85-lb. capacity commercial washing machine (depending upon volume) and an accompanying dryer of the same capacity. The washers are primarily used for laundering wipe rags and reusable mop heads (although not together), as well as cleaning bar wipes and cloth filters. Each fabric and soil load has a separate wash cycle setting provided to us by the equipment manufacturer and fine-tuned by the vendor of the laundry chemicals. Much to our amazement, the multiple wipe rag program worked better than expected and the establishment owners were able to amortize the washers and dryers in less than a year. Wipe rag replacement was between 10% and 25%, depending upon the type of operation.
• As with plastic cutting boards, the rags used in the multiple wipe rag program should be color coded. Each application or use has a specific color impregnated into the rag. This is easily accomplished with the self-laundering program. Wipe rags may also be purchased with a color-coded strip sewn into the rag’s seam or woven into the fabric. By using differently colored rags, total separation of food preparation, service and bar operations and toilet sanitation can be maintained for prevention of cross contamination. Cleaning cloths used to wipe customer tables and seats are not used to wipe any other surfaces and so on. Wipe rags used to wipe service counters, cutting boards, scales and other surfaces that may directly or indirectly contact food are used only once until laundered.
• The multiple wipe rag program has obviated the use of keeping wipe rags in a sanitizing solution. However, for those instances where a sanitizing solution is necessary and used, we provide a larger bucket or pail to facilitate rinsing and wringing. Effective use of wipe rags is a two-handed operation.
• To clean food prep surfaces and areas effectively, always start at the top and work down to avoid re-contaminating already cleaned surfaces. The most critical cleaning of food preparation surfaces is accomplished in several steps.
Step 1. Using a clean rag moistened with an approved detergent and hot water, wipe food particles from the surface. Use a putty knife and/or a white scrubbing pad to loosen adhered materials. Do not allow surfaces to dry before rinsing. If the surface is heavily soiled, apply solution liberally and allow it to soak for 10 to 20 minutes before scrubbing. Several wash/scrub/rinse cycles may be needed if the surface is heavily soiled.
Step 2. Rinse clean all surfaces with hot water using another clean rag. Inspect all surfaces to ensure that no soil, food residue or grease remains.
Step 3. Sanitize all food contact surfaces with a third clean rag wetted with an approved sanitizing solution. Do not rinse; allow to air dry.
Finally, the key to any safe and successful cutting board and wipe rag program lies in management control. A properly written standard sanitation operating procedure (SSOP), along with proper training and oversight, is needed to ensure that the desired levels of cleanliness and sanitation are achieved and maintained throughout a retail food establishment. There is no single right or wrong way to put together a program that works; the bottom line is results. However, according to William R. Griffin, an expert in cleaning, most successful programs have a number of key elements that include the following:
• Upper management must provide ongoing support and encouragement. Cleaning and maintenance must be recognized as an important function. Without this support, no cleaning program will be effective.
• Someone must be responsible and held accountable for each duty or task.
• Workers must know what is expected of them.
• Written procedures must be established and followed (SSOP).
• It must be recognized that cleaning does not stand alone, it must be supported by adequate physical plant systems such as design, layout and construction including lighting (at least 20-ft. candles), ventilation, plumbing (adequate and readily accessible janitorial facilities), safe electrical service (GFIC protected) and resilient washable surface finishes. In addition, cleaning and maintenance must be considered when designing, building and remodeling facilities.
• Ongoing training must be provided at all levels, including worker, supervisor and manager.
• The cleaning program must be flexible enough to meet changing needs (incorporated into the Hazard Analysis and Critical Control Point [HACCP] program).
• The work must be continually inspected, supervised and monitored for quality. Continuous quality improvement, employee involvement and the development of positive attitudes must be a basic premise of operation.
• Periodic duties should be scheduled on a yearly basis and their completion verified and documented.
• Adequate staffing, supervision, budget, supplies and equipment must be provided.
An organized management control program is the key for success when it comes to the prevention of cross contamination in food production and service areas. The alternative is recurring problems, both legally and operationally, frustration with inspection and enforcement activities, and putting staff and customers at risk. Maintaining a safe and satisfactory sanitation program for cutting boards and wipe rags is not difficult.
Also, work with the local sanitarians. They have seen it all and can provide new and innovative ideas tailored to any retail food establishment’s operation.
Forensic sanitarian Robert W. Powitz, Ph.D., MPH, RS, CFSP, is principal consultant and technical director of Old Saybrook, CT-based R.W. Powitz & Associates, a professional corporation of forensic sanitarians who specialize in environmental and public health litigation support services to law firms, insurance companies, governmental agencies and industry. For more than 12 years, he was the Director of Environmental Health and Safety for Wayne State University in Detroit, MI, where he continues to hold the academic rank of adjunct professor in the College of Engineering. Among his honors, Powitz was the recipient of the NSF/NEHA Walter F. Snyder Award for achievement in attaining environmental quality, and the AAS Davis Calvin Wagner Award for excellence as a sanitarian and advancing public health practice. He is the first to hold the title of Diplomate Laureate in the American Academy of Sanitarians, and also is a Diplomate in with the American Board of Forensic Engineering and Technology.
Dr. Powitz can be reached via e-mail at email@example.com or through his website at www.sanitarian.com.
1. Williamson, D.M., Gravani, R.B., and Lawless, H.T. 1992. Correlating food safety knowledge with home food-preparation practices. Food Technol. 46(5):94-100.
2. USDA FSIS. Focus on: Cutting Board Safety. 1997.
3. Ak, N.O., D.O. Cliver and C.W. Kaspar. 1994a. Cutting boards of plastic and wood contaminated experimentally with bacteria.J. Food Protect. 57:16-22.
4. Ak, N.O., D.O. Cliver and C.W. Kaspar. 1994b. Decontamination of plastic and wood cutting boards for kitchen use. J. Food Protect. 57:23-30.
5. Griffin, W.R. 2004. Clean to the extreme! Maintaining kitchen areas in health care facilities. www.Hospitalconnect.com.