29. PREVENTING CONTAMINATION
MODULE 3
PREVENTING
CONTAMINATION
There are many opportunities for foods to be contaminated. This module helps to identify sources of contamination and ways to prevent contamination to foods.

30. Cross-contamination FOOD
Cross-contamination is the transfer of a harmful substance to food by vehicles such as:
CHEMICALS
Cross-contamination is the transfer of a harmful substance to a food by vehicles such as hands, such as human hands, contaminated food contact surfaces of equipment, utensils, or directly from a raw food to a ready-to-eat food.
Examples:
Human Hands-Can carry any variety of contaminates; bacteria, viruses, chemicals, and physical hazards. It takes hands to prepare food. Keep them clean!
Contaminated Food Contact Surfaces-cutting boards, knives, spoons, meat slicers, grinders, etc. Each must be cleaned and sanitized between use.
Raw Foods-can contaminate other foods during storage or by soiled equipment.
Chemicals-cleaning chemicals, degreasers, glass cleaners, pesticides.
FOOD
HANDS
UTENSILS &
EQUIPMENT
BACTERIA

31. How does it happen? Improper storage practices
Contact with food workers
Food and/or ingredient contamination
Contact with food contact surfaces of equipment, utensils, and wiping cloths
Contamination from ice
Contamination by consumers
Cross contamination can occur in many different ways, such as:
Improper storage practices (open food containers)
Contamination by food handlers (soiled hands from touching raw meat)
Food and/or ingredient contamination (during processing)
Contamination of food contact surfaces of equipment, utensils and wiping cloths (dirty wiping cloth used to clean a surface)
Contamination from raw foods (raw chicken dripping on fresh lettuce)
Contamination from ice (ice in seafood displays)
Contamination by consumers (coughing while using the salad bar)

32. Ready-to-eat food items
Foods that do not require cooking or further preparation prior to consumption.
Ready-to-Eat Foods-do not require cooking or further preparation prior to consumption.
Examples:
Precooked foods that do not require further cooking
Raw fruits and vegetables
Candy
Bakery items
Beverages
Ice
Unpastuerized and pasteurized fruit juices
Cross-Contamination commonly happens when bacteria or viruses are transferred to the ready-to-eat food and a cooking step is not in place to eliminate the hazard.
Example:
Bacteria from raw meat can be transferred to a ready-to-eat food such as lettuce for a salad when a cutting board and knife are used without being washed and sanitized between uses.

33. Contamination by food handlers
Sick food service workers
Open cuts, scrapes and burns
Inadequate hand washing
Eating, drinking, or using tobacco
Soiled clothing
Food handlers are probably the most significant sources of cross contamination.
Cross-contamination by a food handler can be the result of:
Coming to work ill-employees must be excluded from food service if they have fever, vomiting, diarrhea, coughing, or sneezing.
Open wounds-all cuts, scrapes, burns must be covered with a clean bandage and a covering such as a disposable glove or clothing.
Hand washing-infrequent or inadequate hand washing is a major method of disease transmission. Proper changing of disposable gloves is important in preventing cross-contamination.
Hand-to-mouth activities-not only can diseases be spread from mouth-to-hand-to food-to consumer, but the food service worker can also be an infected carrier.
Clothing-soiled uniforms and aprons can harbor bacteria. Remind employees to remove aprons before entering restrooms. Hair restraints are required when working with food. They must be kept clean like any other part of the uniform.

34. Protecting stored food
Keep food storage areas clean, sanitary and properly organized
Keep foods covered
Store foods away from toxic items
Store foods on shelves at least six inches above the floor
Prevent insect and rodent infestation
Prevent leakage from overhead pipes
Stored food must be protected from cross-contamination.
Maintain clean, sanitary food storage areas and use the “F.I.F.O” (first-in-first-out) rule. Store ready-to-eat foods above raw foods in refrigerators.
Raw, ready-to-eat foods no cooking
Eggs, fish ºF
Pork, ground beef, game animals ºF
Poultry, stuffed meats ºF
Keep food covered to protect from contaminates such as, airborne contaminates in refrigeration units.
Ensure that all non-food items (such as cleaning and sanitizing agents) and toxic substances are well-labeled and stored separately from food items.
With the exception of cased food packaged in cans, glass or other waterproof containers, all stored foods should be stored at a minimum of six inches above the floor.
Allows for cleaning:mop water can absorb into packaging
Sewage back-ups can happen at any time, product will be saved if stored off the floor.
Insect and rodent infestation is often a problem in retail food establishments. Be sure to talk with a pest control operator and determine the most effective methods to prevent pest infestation in your establishment .
Be sure to prevent leakage from overhead sewage pipes or water lines.

35. Contamination from food contact surfaces
Improperly washed & sanitized equipment
Knives Cutting boards
Grinders Slicers
Improper storage of in-use utensils
Spoons Tongs
Food & ice scoops Frozen dippers
Store equipment in a clean, protected location
Cross-contamination can also occur by contact with contaminated food contact surfaces, utensils or wiping cloths.
It is important that all equipment and utensils (knives, cutting boards, slicers, grinders, etc.) are washed, rinsed and sanitized properly and at proper intervals.
Improper storage of in-use food utensils (i.e. dispensing scoops, frozen dippers, etc.) can also lead to cross-contamination.
Food scoops & tongs-in product at the same temperature as the food item. All food dispensing utensils must have a handle to prevent hand contact contamination. The handle must not be in the food.
Ice scoops-in a holster, on a tray or in the product stored “handle up” to prevent hand contact contamination.
Frozen dippers-in a dipper well with continuous potable running water.
Equipment should be stored in a clean protected location.

36. Contamination from wiping cloths
DO NOT store cloths on equipment or preparation surfaces
Store wiping cloths in sanitizer when not in use
Use paper towels when utilizing sanitizer from a spray bottle
Wiping cloth-moist cloth or sponge used for wiping food debris on kitchenware, food and non-food contact surfaces.
Dirty wiping cloths can contaminate anything they touch. The have food particles (protein) and moisture that can support the growth of bacteria when stored at room temperature.
When not in use, store wiping cloths in a sanitizing solution.
DO NOT store wiping cloths on equipment or preparation surfaces. Air contact can break down the sanitizing agent.

37. Cleaning and sanitizing
Utensil washing
By hand
Mechanical
equipment
Food contact surfaces
Cleaning-in-place equipment
Utensil Washing-
By Hand-3Bay Sink; 1-wash, 2-rinse, 3-sanitize
Chemical-50ppmCl for 10 seconds, 200ppm Quat, 12.5 ppm Iodine for 30 seconds
Heat-greater than 170ºF for 30 seconds
Mechanical -
Hot Water ºF Wash, ºF Rinse
Chemical ºF Wash,
Sanitizer 50 ppm Cl for 10 seconds, 200 ppm Quat,
12.5 ppm Iodine for 30 seconds
Food Contact Surfaces-Countertops, cutting boards, commonly used utensils, etc..
In-place Sanitizer-Bucket or spray bottle with an approved sanitizer
[100 ppm Cl, 200 ppm Quat, 12.5 ppm Iodine]
Clean Surfaces- between raw animal products and ready to eat foods
In-Place Equipment-
1-wash, 2-rinse, 3-sanitize [50 ppm Cl, 200 ppm Quat,
12.5 ppm Iodine] .

38. Sanitizer concentrations  
Cleaning-removal of visible soil, such as crumbs and spills.
Sanitizing-reduction of disease causing micro-organisms to a safe level.
In-place sanitizer-is to be utilized for sanitizing work stations and equipment between instances of contamination.
Example: between processing raw and ready-to-eat foods, clean and sanitize work area, cutting boards and knives.
Mix chemicals with lukewarm water. Each work station should have in-place sanitizing available. Change frequently throughout shifts, food debris will break down the concentration of chemicals.
All sanitizers must be EPA approved.
Follow all directions on sanitizer labels.
Chlorine ppm
Quaternary Ammonia ppm
Iodine ppm

39. Contamination from ice
Product packaging
Food displays
Cooling
Ice is a food.
Ice is a single use item when used as a coolant.
Examples: A vehicle for cross contamination
Dripping of ice-packed raw chicken onto ready-to-eat food products (i.e. produce).
Improper separation of raw seafood from ready-to-eat seafood in an iced-down display unit.
Ice used as a cooling medium for food storage must not be used or sold for human consumption.

40. Cross-contamination from consumers
Provide sneeze guards for food displays, service lines, and self-service areas
Provide clean tableware for second portions and refills
Have provisions for condiment protection
Cross-contamination can also occur when consumers or customers handle food.
To prevent cross contamination by consumers:
Provide protective devices such as sneeze guards for food displays, service lines, and customer self-service areas
Provide clean tableware for second portions and refills
Enforce policies for refill of personal take-out beverage containers
Have provisions for condiment protection

41. Demonstration for in-place sanitizers and wiping cloths
This demonstration is intended to show how to prepare an in-place sanitizer. It is also helpful is teaching how to use chemical sanitizer test strips.
After this demonstration, go to the bacterial growth slide for 90 minutes.