Home > Cross Contamination and Sanitation

Cross-contamination: Involves the spread of harmful microorganisms or chemicals to food that is ready to eat.

Ready-to-eat foods: are those that can be eaten as is. These include all cooked and heat processed foods even if they have been cooled or frozen (e.g. washed vegetables, cooked meats, salads etc.)

Pathogens: Disease-causing microorganisms

Cross-Contamination:

Cross-contamination may occur when pathogens or food allergens are passed from one food item to another, or when foods come into contact with contaminated surfaces, utensils, equipment or hands.

The three main sources of cross-contamination are:

1. Hands: Contaminated hands touching food
2. Food: improper handling and storage of food
3. Equipment: using the same equipment or utensils to handle raw food and ready-to-eat food

Hands

A food handler’s hands come into contact with many unclean surfaces, equipment, food and other items. It is therefore important that frequent and proper handwashing techniques are practiced.

Food

Food may become contaminated if not stored properly. Raw meats, poultry, fish, seafood and raw produce may contain pathogens. It is therefore important that all raw foods are stored separately from cooked and ready-to-eat foods.

An example of cross-contamination due to improper food storage includes placing raw meat on a shelf above ready-to-eat foods such as salad. Blood or liquids may drip from the meat onto salad and go unnoticed.

Equipment

Ready-to-eat foods may become contaminated if they come into contact with equipment or wiping cloths that contain pathogens or allergens.

Items which may transmit pathogens or allergens to ready-to-eat food include:

• Food Contact Surfaces: work tables, cutting boards
• Equipment: slicing machines, meat grinders, mixers, probe thermometers
• Utensils: knives, forks, tongs

Examples of cross-contamination between raw and ready-to-eat foods:

• Raw chicken is cut on cutting board
• Pathogens from the chicken are passed onto the board, knife and the food handler’s hands
• A cooked chicken is cut on the same board with the same knife (all had been contaminated with the raw chicken).
• Pathogens are passed from the contaminated cutting board and knife to the cooked chicken.

Example of cross-contamination between food and an allergen:

• Nuts are chopped on a cutting board
• Oils and residue are passed from nuts to cutting board and utensils
• Raw vegetables are sliced on the same cutting board with the same utensils
• Oils and residue are passed from the cutting board and utensils to the vegetables

Preventing Cross-Contamination:

• Wash hands properly and frequently
• All cooked and ready-to-eat items requiring refrigeration must be covered or wrapped and stored above raw meats, poultry, fish and seafood in cold storage units.
• During cold storage, all raw meats should be stored on bottom shelves and cooked and ready-to-eat foods on upper shelves
• When possible, all raw meats should be stored in separate cold storage units, away from ready-to-eat foods.
• Have separate food contact surfaces, equipment and utensils for raw and ready-to-eat food and for foods that contain allergens
• All cutting boards and food contact surfaces must be smooth, free of crakes and pits to allow for proper cleaning and sanitizing
• All food contact surfaces or equipment must be washed, rinsed and sanitized immediately after each use.
• Whipping a contaminated knife or cutting board with a cloth us not sufficient to remove pathogens or allergens. If the contaminated cloth is then used to wipe other surfaces, equipment, utensils or hands, pathogens or allergens will spread.
• The probe thermometer must be sanitized before and after inserting it into food

Cleaning and Sanitizing:

Microorganisms can be passed from person to person by both dishes and utensils, therefore proper manual or mechanical dishwashing is important in preventing the spread of pathogens.

Cleaning the removal of visible dirt, oil, grease and organic matter from an object using detergent warm water and scrubbing

Note: Cleaning helps to remove pathogens, but it does not kill those that remain. Cleaning must always be a step in removing pathogens. If surfaces are not “clean”, heat or chemical sanitizing steps will not work properly.

Sanitizing: A process that reduces pathogenic organisms to acceptable levels using either hot water or chemical agents

Approved Sanitizers:

• Hot Water
• Chemical Sanitizers: For a minimum of 45 seconds
  • Chlorine, Quaternary ammonium compound (Quats), Iodine

Note:

• To ensure proper sanitizing strengths, solutions must be prepared daily and changed frequently
• Appropriate test strips/reagents must be used to measures the solution strength and verify proper concentrations
• Label all sanitizing solutions to ensure chemicals are not misused as a food ingredients
• Always follow the manufacturer’s directions on the product labels

Manual Dishwashing

Three sinks are required to clean and sanitize multi-use/re-usable eating utensils, pots and pans

The method consists of:

• Wash in the first compartment, wash utensils and equipment in clean, hot, soapy water
• Rinse in the second compartment, rinse utensils and equipment in clean water of at least 43°C to remove soap and any remaining food particles
• Sanitize in the third compartment, sanitize utensils and equipment for at least 45 seconds in an approved sanitizer

Wash in place for large Equipment and Surfaces

This process must be used to wash and sanitize equipment that is too large and does not fit in a sink or mechanical dishwasher. All food contact surfaces must also be cleaned and sanitized after each use.

The method consists of:

1. Wash equipment with warm and detergent solution
2. Risen with clean water
3. Sanitize with hot water at a minimum of 82°C or an approved chemical solution at double strength for chlorinated chemicals; follow manufacturer’s instructions for “Quats” and Iodine.
4. Air dry

Wiping Cloths

Wiping cloths stored in sanitizing solutions are used to sanitize surfaces

• Wiping cloths are to be maintained clean and in good repair
• The cloths are to be stored in one of the three approved chemical sanitizer solutions at manufacturer’s suggested concentrations
• The sanitizing solution must be prepared daily and changed frequently
• If the sanitizing solution is stored in a spray bottle, it must be labelled
• Test strips/reagents must be used to measure the solution strength and verify proper concentration

Mechanical Dishwashing:

High Temperature Dishwasher:

Uses hot water in the rinse cycle to sanitize

• The wash water temperature must not be lower than 60° C and not higher than 71°
• The rinse water temperature must be a minimum of 82° C and the cycle must last at least 10 seconds

Low Temperature Dishwasher:

Three approved chemical sanitizers:

• Chlorine: Minimum 100 ppm
• Quaternary Ammonium Compounds (“Quats”): Minimum 200 ppm
• Iodine: Minimum 25 ppm

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