Cleaning & Sanitizing
First, it must be remembered that all food contact surfaces must be clean and sanitized. Sounds easy, but this encompasses quite a bit. Clean is easily understood, but what is meant by “sanitized?” Several answers are suggested. The usual answer is: “free from organisms,” however this term more closely defines “sterilized,” which might describe equipment used in surgery. Another answer often given is: “free of dirt,” but this comes closer to the definition of “clean.”
Give up? OK, here’s the answer. Sanitize is defined as:
“…reducing pathogens to a safe level.” This is further explained in the Food Code as “a 99.999% reduction of microorganisms of a public health importance.”
The code states that all equipment food contact surfaces and utensils must be sanitized. This includes cooking equipment, work surfaces, plates, glasses, etc. Word-quibbling aside, the important question is “How can we do this?”
Methods of Sanitizing
Besides heat, sanitizing may also be accomplished with chemicals. Some dish machines use chemicals for sanitizing. Even though these machines are called low temp machines, the water temperature is usually 140°F (60°C) — hot enough to burn the skin. Because the surface of utensils will not reach 165°F (74°C) in this system, chemicals are added to the final rinse. There are three chemicals commonly used for this purpose: chlorine, iodine and quaternary ammonium (not the same thing as household ammonia.) Each has its own advantages and characteristics.
Chemical Sanitizer
As you examine the various sanitizer below, note the importance of immersion time and concentration.
CHLORINE
Concentration Range: 50-99 ppm
Temperature of Solution: 75-125°F (27-52°C)
Time for Sanitizing: 1 min. read label
Response to Food and Detergents: Quickly inactivated
Test for Effectiveness: Requires test strips
IODINE
Concentration Range: 12.5-25 ppm
Temperature of Solution: 68-120°F (20-49°C)
Time for Sanitizing: 1 min. read label
Response to Food and Detergents: Less effective
Test for Effectiveness: Requires test strips
QUATERNARY AMMONIUM
Concentration Range: 200 ppm (FDA Code suggests following EPA registered label use instructions)
Temperature of Solution: 75°F+ (27°C+)
Time for Sanitizing: 1 min. read label
Response to Food and Detergents: Not easily effected
Test for Effectiveness: Requires test strips
All chemical sanitizer require verification of concentration using test strips which should be supplied by the chemical purveyor. Without test strips, it is impossible to tell if the concentration is too weak and failing to sanitize, or too high and leaving a toxic residue. It is amazing how frequently food establishments admit that they never test the strength of their sanitizer, or do so only once per day. This provides a false sense of security and is a tremendous waste of money.
Sanitizer strength is influenced by several factors, one of which is use. Exposure to bacteria and other organic particles causes a weakening of the chemical effectiveness. This is especially true of chlorine, which will become ineffective in the presence of food particles, even in small amounts.
Facilities which rely on two-compartment sinks for ware washing and place chlorine in the second sink for sanitizing are usually surprised to find that their sanitizing program may be quite ineffective.
Recently, I visited a food establishment and observed the three-compartment sink process. The third sink was filled with room temperature water and dishes. The solution had no recognizable odor of chlorine. I inquired as to when the solution was prepared and was told, “10:30 in the morning.” The time of the visit was 1 p.m. When tested, the solution did not even register on the test strips.
Safety Data Sheets
Various chemicals are used in cleaning and sanitizing a food establishment. Remember that these must be stored away from food. Also, the Occupational Safety and Health Administration (OSHA) requires that Safety Data Sheets (SDS) be kept for all chemicals. These sheets are prepared by chemical manufactures and must be maintained in files within the food establishment to provide information to food workers concerning the hazards of the chemicals being used.
The Three-Compartment Sink
The three-compartment sink is commonly used in food establishments for cleaning and sanitizing. For effectiveness, it is important that the sinks be used in the proper order.
- The first sink is used for washing. Food should have been scraped from the surface first and surfaces may need to soak before washing to soften stubborn food areas. Water in this sink should be as hot as is comfortable and should be changed as needed to keep the detergent fresh.
- Sink number two is used for rinsing off food particles and soap residue. This water should also be hot.
- The last sink is used for sanitizing and should be maintained at the correct concentration as noted above. It is critical that the manufacturers’ directions be followed concerning immersion time, concentration and water temperature.
Finally, utensils need to air dry. No towels should be used for drying. (My kids were thrilled to hear this part!) Ideally, the drying process should be completed in 15 minutes. In no case should utensils be put away wet, as moisture encourages the growth of microorganisms. An additional word about storage: traffic patterns in a food establishment should be arranged so that dirty dishes never cross with clean ones. As an example, a water glass that has been emptied may look clean, but isn’t and could potentially contaminate the cleaning and sanitizing you have done.
Biofilms and Equipment
As we approach the subject of cleaning fixed equipment such as work surfaces, a discussion of biofilms may help cure complacency. Biofilms are defined as “microcolonies of bacteria closely associated with an inert surface attached by a matrix of complex polysaccharide-like material in which other debris including nutrients, microbes and viruses may be trapped”.
To simplify: when a microbe contacts a surface, it attaches itself with appendages and tendrils that adhere to cracks and crevices of even stainless steel. Within 20 min., this attachment can become quite tenacious. Several layers can accumulate over time, complete with pathogens including Salmonella, Listeria, and Staph.
Sanitizing agents of these surfaces are ineffective if the biofilm has not been removed, as sanitizer will not penetrate biofilms. Hot water, detergent and mechanical action such as a scrub brush must be applied to remove these films.
Some instructors recommend that all food preparation should take place on removable cutting boards that are more effectively cleaned. Whichever the case, the food preparation surface must be sanitized. This is best accomplished with hot water, detergent and a brush as mentioned above, followed by a spray application of sanitizer in the appropriate concentration. Again, the cleaned items must be allowed to air dry.
Cleaning Fixed Equipment
Equipment that is fixed in place (such as soft serve yogurt machines, mixers and slicers) may be cleaned by first disassembling and running all available parts through the normal sanitizing procedures. Then by cleaning the remaining parts of the equipment with hot water, soap and brush. Rinse thoroughly. Spray with a sanitizing solution, allow to air dry. Reassemble the equipment and re-sanitize any food contact surfaces that may have been contaminated in the process.
Key Elements of Cleaning Fixed Equipment
- Disassemble, clean and sanitize removable parts
- Clean non-movable parts with hot water and soap
- Rinse
- Air Dry
- Spray with a sanitizing solution
- Reassemble
- Re-sanitize any surfaces which may have become contaminated during reassembly
Cleaning Schedules
With all this in mind, how is a food establishment kept clean? Consider a home kitchen and the issue of “it’s not my job.” Amplify this 100 times and the problem becomes depressingly clear. The use of cleaning schedules makes the cleaning process easy to maintain.
A cleaning schedule must have every surface in the establishment listed. If it is not on someone’s schedule it will remain dirty. The schedule also should list who is to clean it, frequency of cleaning and procedures and equipment to use. These directions should be placed near the workstation of the individual responsible. A simple checklist should be completed by the closing supervisor.
Protecting the Environment
Water
Care should be taken to prevent pollution of the environment by the food establishment. Good management practices are required to prevent urban runoff pollutants from degrading water quality. The Clean Water Act, established in 1977, makes discharging pollutants into navigable water illegal without a permit. It is the original authority for protecting water in the United States from pollution. The following stipulations are
applicable to this course:
- floor mats and garbage cans should be washed in mop sinks not in parking lots or streets
- grease and oil must be recycled, not poured into sinks, floor drains or streets
- liquid wastes should not be poured into dumpsters
- dumpsters should not be cleaned by hosing out; allow the dumpster service to clean these pieces of equipment
Fats, Oil and Grease (FOG)
The cumulative effect of food establishments (and homes) dumping grease used in cooking down drains creates extreme public health hazards. Grease from food preparation operations solidifies on the inside of the sewer pipes restricting the flow of sewage. Eventually, pipes clog, and spills occur in the sewage lines. Considering that restaurants can typically go through 50 to 100 gallons of grease per week, the issue of proper grease disposal becomes even more pressing.
Discharge of fats, oil and grease (FOG) from commercial food operations is a major contributor to sewer spills, manhole overflows and system blockages.
Typically, FOG enter a facility’s plumbing system from warewashing, floor cleaning and equipment sanitation and discharge of grease down the drain. The best way to prevent inappropriate accumulation in the municipal sewer system is to develop best management practices (BMPs) within each operation.
Depending on the type of operation, BMPs may include use of a grease interceptor, grease trap or simply procedures designed to prevent FOG from entering the sewer system. Such procedures may include:
- Dry clean up: food surfaces such as counters and pans should be wiped with paper towels before washing. In addition, any spills from products should be dry cleaned first prior to washing.
- No food debris should be put down the garbage disposal.
- No liquid fats, oil or grease should be put into sinks, toilets or floor drains.
- All food wastes should be wrapped and disposed of in the trash.
- Any waste fat materials should be collected for recycling.
- No biological agents for grease treatment should be used.
- No equipment should be cleaned outdoors in an area where water can flow to the gutter, storm drain, or street.
Trash
Maintenance of garbage areas is important for the control of odors and pests. We will be discussing pest control thoroughly in the next module. Correct garbage maintenance is also important for the protection of the environment. A leaking dumpster presents numerous problems for the environment as well as attracting rodents and birds.
Maintain the garbage areas in a clean manner. Garbage must be removed often enough to prevent the problems mentioned above. Dumpsters must be cleaned regularly and be closed with lids in place. When place in dumpsters, garbage must be in leak proof containers or bags. Any garbage not placed in a dumpster, must be in a sturdy container with a tight fitting lid. Plastic bags are not to be placed in the open where they may be easily torn open by animals.
Garbage containers in the food preparation area should be covered except when in use. They should be lined with plastic or wet-strength paper bags for ease of removal of contents and cleaning.
Suggestions for Home
A few suggestions for home use may be appreciated. We sanitize very little, if at all, at home. Items in our dishwasher may reach 165°F (74°C) depending on the type of dry cycle used. I have never seen a three-compartment sink in a home kitchen, although some may be adaptable to this concept.
Certain precautions may be reasonable, however. Try not to place any food directly on counter tops. By no means place any raw protein product directly on these surfaces; use plates, plastic wrap or cutting boards.
After performing a task with an item that may be particularly worrisome, such as skinning chicken, dilute about 1/4 teaspoon of bleach in 20 oz of water (a little over a pint). Use this solution to wipe surfaces. Buy a small bottle of bleach and keep it for this purpose. (If there are small children present, store in a high location.) Don’t transfer the bleach to a different container for safety purposes, and remember light dissipates chlorine, so don’t ever keep it in a translucent bottle. Household products that use the words “disinfectant,” “antibacterial” and “sanitize” usually do a reasonably good job against Salmonella, and Staph.
One last suggestion concerns the impression you may gather from a dumpster when choosing a restaurant. Some dumpsters are shared by several food establishments, so the evaluation of these is not as useful, but when choosing a restaurant, take a peek at the dumpster. If it is a food-strewn, maggot-filled, stinky mess, chances are the food safety systems are not very good in that food establishment.
On the contrary, if the dumpster is reasonably well maintained, food is contained and it looks like it is cleaned occasionally, chances are the food safety systems are in fairly good shape in that establishment. No guarantee on this, but I have never seen it fail.