Contamination occurs when something not normally found in the food is added. Contamination implies the addition is not intended or planned. The substance added may or may not cause problems. Three main sources of contamination are from physical, chemical, and microbial sources.

Physical Contaminants Physical contaminants are substances that become part of a food mixture. They may not change or damage the food itself. However, their presence can create health hazards for the consumer. For instance, metal filings or broken pieces of glass have occasionally gotten into foods. These materials would not spoil food, but they could cause injury if swallowed.

Chemical Contaminants Keeping insects and other pests under control can lead to chemical contamination. Insecticides are chemicals used to improve crop yields by reducing losses due to insects. Herbicides are used for the same reasons to control weeds. Both types of substances are pesticides. If pesticide residues remain on food, they enter the food supply.

Correct food handling practice and food storage helps prevent bacteria from contaminating and multiplying on foods. The following action needs to be taken to prevent bacterial contamination:

• Protect food from contamination – handle food properly
• Prevent bacteria from multiplying
• Destroy germs on/in food

Fig. 3.33: The food contamination chain can be broken in several places.

Food can be protected from contamination by handling it with care. Food handlers should think about:

• where food poisoning bacteria come from. They can come from people's bodies, sneezes, coughs, high risk foods, insects, rodents, pets, toilets and dust particles in the air
• the different ways bacteria can get on to the food they are handling, for example, from cross contamination and contaminated hands and clothing
• the correct cooking and storage temperatures which prevent bacteria multiplying

The number of people affected in an outbreak of food poisoning will depend on where the food contamination occurs. For example, contaminated food prepared and eaten in the home is only likely to affect a few people but contaminated food prepared in a fast food outlet or in a factory is likely to affect many people.



 

1 Correct food handling rules

Always wash hands with soap and warm water before handling food. Wet the hands before applying the soap. Make sure you rub in between fingers and on the front and backs of hands. Remember to clean under fingernails. Rubbing with soap loosens bacteria. They must be rinsed off with water. (When possible, use hot water for washing the hands.)
 

Fig. 3.33: The food contamination chain can be broken in several places.

Food can be protected from contamination by handling it with care. Food handlers should think about:

• where food poisoning bacteria come from. They can come from people's bodies, sneezes, coughs, high risk foods, insects, rodents, pets, toilets and dust particles in the air
• the different ways bacteria can get on to the food they are handling, for example, from cross contamination and contaminated hands and clothing
• the correct cooking and storage temperatures which prevent bacteria multiplying

The number of people affected in an outbreak of food poisoning will depend on where the food contamination occurs. For example, contaminated food prepared and eaten in the home is only likely to affect a few people but contaminated food prepared in a fast food outlet or in a factory is likely to affect many people.



 

1 Correct food handling rules

Always wash hands with soap and warm water before handling food. Wet the hands before applying the soap. Make sure you rub in between fingers and on the front and backs of hands. Remember to clean under fingernails. Rubbing with soap loosens bacteria. They must be rinsed off with water. (When possible, use hot water for washing the hands.)
____ ______ ______ _______ _________ ______.
________ ________ ____ ___ _____ _____ ____ _____ ___ ___ _________ _________.
______ ___ _________ _____ ___ __________ ___ _____.
_______ _______ ____ _________ ________ ______ __________ _____ _________ _____.
____ ______ ____ _______ _____ ________ ________ ____.
____ __________ _______ _______ _____ _______ ___.
_______ _____ __________ ___ __________ _______ ________ ________.
_________ _____ _____ ________ _______ ________ __________ ____.
____ ______ ___ ________ __________.
______ ____ _________ _____ ___ ______ __________ _____ ________ ________.
_______ _______ ___ _____ __________ __________ _________ ____ _____ _____ _______ _________.
________ _________ _______ __________ ___ _____ ______ ____ ______.
______ _____ _____ ______ _______ ___ ______ _____ __________.
____ ________ _______ ____ ________ __________ ____ ______.
____ _____ _________ __________ ______ __________ _________ _____.
_____ _________ ______ __________ ___.
______ ___ ______ _____ ________ __________ _____ ____ ________.
_________ ___ _______ _____ ______ __________.
_____ ___ ___ _____ _____ ____ __________ ____ _________ ________ ______.
__________ _______ ___ _______ _________ _______ ____ ___ ____ ________ ___ _______.
_____ ______ _______ __________ ________ _____.
___ ____ ________ _________ ______.
________ ___ ______ ________ _____ ______ ____ ______ ______.
___ __________ ________ ________ __________ ______ ___.
____ ______ ________ _____ __________ _______ _______ _____ _____ ______ ________.
___ ___ _________ ______ ____.
__________ ___ _____ ________ ____ ______ ______ _____ ___ _______ __________.
________ _________ ________ ___ __________ _______ ________ ______ _______.
__________ ____ _______ ______ _________ ________ ____ ____.
___ ____ ______ ________ ____ _____.
______ ________ ____ ______ ______ ______ _____ ____ _____ ____ ____.
__________ ___ ________ ________ ____ ________ __________ _________ ________ ___ _________.
__________ ________ _________ __________ ____.
______ _________ _________ ____ _____ _________ _________ _______ ________ __________ ____.
______ ___ ___ __________ _________ ________ _____ ___ __________ _____ _______ ____.
_______ ____ ____ ____ __________ _________ ___.
________ ____ ___ __________ _________ __________ _______ ____ ___ ___ _______ ____.
__________ ________ _________ _________ _________ _____ __________ ________ _______ _____ _____.
________ _______ __________ _____ _________ ___ ___ _______.
_____ _____ _____ ________ ___ ___.
____ ____ __________ _______ ______ _____ _______.
___ __________ ______ ______ _______ ___ ___ ________ ___ ___ _______ ________.
_________ __________ ___ _______ _______ _____.
____ _________ ____ _______ _________ _________ _______ __________ ___ _____ ___ ________.
______ ________ ____ ___ _____ ______ ______ __________ ____.
__________ __________ ______ ____ __________ _______ ________.
____ _______ ______ ____ _____ ____ ________ _________ _____ ________ ___.
________ ______ _______ ________ ______ ________ ___ _____ _________.
_________ _______ _________ ____ ____ _____ ____.
________ __________ _________ ___ _____ _________ ________ _____ ________ ______.
______ ___ _____ _____ __________ _________ _____ _________ _____.
__________ ______ _____ _________ ___ _____ ___ ________ __________ ________ ___ _______.
______ __________ _________ ________ ______.
______ _______ ______ _________ _______ _____.
________ _____ ___ ___ __________ __________ ________.
____ ________ ______ _______ ____ ______ ________ _____ __________ ___.
___ _________ ___ ___ _____ __________ ___ ________ __________.
________ _________ _________ ________ ________ __________ _______ _____ __________ _______ ___ _________.
___ _________ _________ ___ ___ ____ ______ ____ ________ ___.
______ _______ ____ ________ ______ ____ _____ __________ __________ _______.
________ ______ _______ _______ ___ ________ _________.
______ __________ _______ _________ _________ _______.
_____ _____ ______ ________ ____ _____ __________ ______ __________ _______ ____ ______.
___ ________ ______ _________ ________ ___.
___ ____ ___ ________ ____.
______ __________ _________ __________ _________ _________ _____ _______ ________ _________ _________ __________.
_________ _______ ___ _________ _________ _____ _______.
__________ ______ ______ ___ _______ ___ __________ ________.
__________ __________ _____ _________ ___ ______ _______ __________ _________ __________.
______ _________ __________ _______ __________ ________.
_______ _____ _________ _________ __________ ___ __________ __________.
________ _____ ___ _____ _____ __________ ______ __________.
______ _______ ________ _______ ______ __________ _____ ________ __________ ______.
_______ _____ ___ _________ ____ ____ _____.
__________ _____ __________ ____ _______ ________.
____ __________ ___ _______ ____ ______ __________.
_________ __________ __________ _____ ____ _______ __________ ____ __________.
_________ ______ ______ _________ _________ _________ _______ ______ _____ _____.
_____ ____ _______ ____ ________ _________ ______ _________ ________ ______ _____ _____.
___ _________ _________ _________ _____ _________ _____ ________ ___ ____.
_____ ___ ________ ____ ___ ___ _________ ______ _______.
__________ ____ _______ ___ _____.
______ _____ ___ _______ _____ ________ _____ ________ ______ ______ _____.
__________ __________ ____ ___ ____ ____.
_____ ______ ______ _______ ____ _______ ___ ___ _____.
_____ ________ ____ _____ __________ _________ _______ ____ ______ ___ ______.
__________ ___ ___ ______ __________ ____ ________ ______ ______ _____ __________ _________.
_____ __________ _____ ____ __________ _____.
______ ________ _______ ______ __________ ____ _________ _______ ______ _______ ________.
_______ ___ __________ _____ _____ ______ __________ _____ ___ ___ ________ ___.
______ ___ __________ ____ _________ _________ _____ ________ ______ _________ ____.
___ ________ _______ _______ __________ ___ ___.
_____ __________ _____ _______ ______ ____ _____ _______ ______ __________ ___.
__________ _________ ________ ______ ______ _________ ____ ________ ______ _____.
________ __________ ______ _______ _________ ___ ______ _____ ____ ___ ___.
__________ _____ _______ ______ __________ ____ ______ ____ _____.
_______ _________ __________ _____ _______ _____.
_____ _____ _________ ____ ____.
___ _______ _____ _____ _____ __________ ______ _______ ________ ____ ___.
_______ __________ ____ ________ _______.
______ _________ _____ ______ ________ ______ ___ ______ _________ _________ ____.
__________ ___ _____ __________ ________ _______ ______ ______ _______ _____ __________.
______ __________ ___ ______ ___ _____ __________ _________.
____ ___ __________ __________ _________.
______ _____ _____ ___ ____ _____ __________ ____ ________.
___ _______ _________ ___ ________ _______ ____ _______ _________ _______ ______ ____.
___ ___ ____ _________ _______ _____ ___ ________ _______.
___ __________ _________ ____ ________ __________.
_________ ____ _________ ________ _________.
____ ___ _______ _______ _____ ___ ___ _________ ______ _________ ____.
____ ____ ________ __________ __________ ___ _____ _________ ___ _____ __________.
____ _______ ________ __________ _________ ___ ______.
___ ________ __________ _____ ____ __________ ________ ____ ____ _________.
________ __________ _____ ___ ________ ________ _________ ____ ___ _________ _____ ___.
_______ ________ ____ ___ ____ ___ ___ _______ ______.
____ ____ ________ _____ ________ _____ _______ ________ ___ _______ ________.
_______ ______ ______ _______ ______ ________ ______ __________ __________ _____ ___.
___ ___ _______ ______ ___ _______.
__________ _____ __________ ____ __________ ______ ___.
____ ________ __________ ____ ___ __________ __________ _____ ______ _____ ___.
_________ _____ ______ ______ ______ ________ ______ ____.
___ _________ ___ ________ _____.
_________ _______ _________ ________ ____ ____ ____.
__________ _______ _________ ______ _______ _________ ____ _________ _____ _________ ______ ________.
______ ______ __________ ___ _______ ________ __________.
__________ ________ _______ _________ _____ _____ _______ ________ ____ _________.
_____ _____ _______ _______ _________ _________ __________ __________ ______ ________ ________.
____ ______ ____ _________ ________ __________ __________ _________ ______.
________ ______ ________ ______ ________ ________ __________ __________ _______ ___.
____ ______ __________ _______ _______.
___ ________ ____ _____ _____ ______ _________ _________ _________.
_________ ____ _______ ___ _____ _________ ________ __________ ______ _________.
___ _______ ______ ______ ______ _____ ________ __________ _____ _______ _________.
________ _______ __________ __________ ________ _________.
_______ _____ ____ _________ ___ ___ _______ ___.
________ ________ _____ ________ ______ _______ ______ ___ ___.
___ _________ ____ __________ ________ ______ ________ _______.
_______ ________ ______ _______ _______ ___ __________ _________ ___ _________.
_________ _______ _________ ___ _______ ________ ______ ________ ____ __________.
____ _________ _________ _______ _______ ______ ______ ____.
_________ _________ __________ ___ ___.
_____ _________ ___ ______ ________ _______.
______ ____ ________ ____ _____.
__________ __________ __________ _________ _________ _____ _______ _______ ____ ______ __________ _______.
_______ ______ ____ ___ ___ _______ ______ ___ ______ _______ __________ ________.
_____ __________ ________ ________ __________ _________.
_______ _______ ___ ____ __________ __________ ___.
________ _________ ______ ________ ___ __________ _________ ________.
________ _____ ________ _______ ___ _______ ____ ____.
____ _____ ___ __________ _____ ________ ___ ________ _________ _________.
_______ ________ ____ ______ _____ ___ _______ _______ ____ ____.
_____ ____ _____ _________ _____ ___ _________ _____ _______ __________ ____ ______.
________ _______ ________ _________ ___ ____ _____ ______ _________ ____ ________.
________ _________ _______ _______ _____ _________ __________ ______.
______ ____ _________ ___ __________ __________ _______ ____ _________ ___ ___ __________.
______ ________ ___ ___ _____ ____ ___ ______ _____ _____.
______ ____ ___ ________ __________ ___ ___ ____ _______ __________ ______ ______.
_________ _____ ___ __________ ___ _____ ___ _________ ______ ________ _________ ___.
________ ______ ____ ______ ________ ________.
___ ______ _______ ___ _________ _________ _____ _____ ___ __________ _______.
_______ __________ __________ __________ ____ ____ __________ _____ ________.
________ _______ ____ ___ _____ ________ __________ ___ ____ ______.
__________ ______ ___ _______ _________ _________ _____ ________ __________ ______ ________ _____.
___ _____ __________ _____ ______ ______ ___ _________ _____.
________ ________ ___ __________ _______ __________ _____ ___.
_______ ____ ____ _______ ___ _____ _______ ____ _____.
____ __________ _______ ____ ______ _______ _______ ____ _________ ______ _______ _________.
_________ ________ _____ _________ ________ ________ ___ ________ ________ ________ ________ _________.
_________ ____ ______ ___ _______ ___ _________ _______ ___.
________ ________ _________ ______ ___ __________ ____ ______ _______ ____.
______ __________ ____ _______ _________ ____ ________ _______ ________.
______ _______ ________ ________ ______ ____ ______.
_______ __________ _________ _______ ______ ___ ______.
___ ____ _________ _________ _________.
____ __________ ___ ____ _______.
___ ______ ___ _______ ________.
_________ ______ _____ ____ _____ _____ ___.
___ ________ _________ ______ _________ __________ ______ ___ ________ _________ _________.
______ _________ ___ _________ ____ _______ ______ _________ ____ _______ _________.
____ _______ ____ ____ ___ ______.
________ ________ ______ ________ _________ __________ _____ ____.
_____ ___ _____ _____ ___ ______.
________ __________ ______ ______ __________ ______.
____ ____ ____ ______ _____ ____ ______ _____ ______ ___.
_____ _______ _____ _____ ________ _______ ______ __________ _______ ______.
___ ______ ____ ____ ______ _________ ___ ______ ____ __________.
______ _____ ___ ____ __________ _______ _________ ______ _________ _____.
____ ________ ________ ____ _____ ___ _________.
______ _____ ________ __________ __________ __________ ___ _________ ____.
_____ __________ ____ _______ ___ _______.
_______ ________ ___ ______ __________ ___ ___ _________ ________ _______ __________ _____.
__________ _____ ________ _________ _________ _________ ________ ____ _________ _________ _____.
______ _________ ___ ________ __________ ___ ___.
______ _____ ___ _______ _______ _________ _____ _______ ___.
_____ ______ __________ ___ ___ _______.
____ ________ ________ _______ _____ ____ _____ __________ ________ _____.
______ ________ _________ ____ ____.
______ ________ __________ __________ _________ _________.
_______ ________ ________ _____ ________ ______ _______ ___ _________ ______ ________ __________.
_________ ______ _______ ______ ________ __________ _________ ________ ______ ____.
____ ______ _______ ____ __________ ___ ________ _______ _____ _________ ______.
____ _______ ________ ____ ________ ___.
_____ _________ ___ ___ __________ _____ __________ _____ ________ ______ __________ ___.
________ _____ _______ ________ __________ __________ _______ ______ ______ _________ ___.
________ ___ _________ __________ _______ ___.
_________ _________ ________ _____ ________ ___ _____ ____ __________ __________.
_________ ____ _________ _____ ___ ___ ________ _________ __________ _______.
___ ______ __________ ____ _________ __________.
________ ____ _________ _______ _______.
________ ___ _____ ___ ____ _________.
_____ ______ ___ __________ ___ ___ _________.
_____ ______ _____ ______ __________ _____ _____ _____ ___ ___ ________ _________.
_____ _____ _____ _______ _______ ____ _____.
__________ _________ _________ _________ _________ ______ _________ ____ ___.
________ _____ _______ _______ ___.
__________ _________ _________ _____ _____ _________ __________.
___ _______ __________ __________ ____.
___ _______ _______ ________ _________ ___ ___.
______ ___ _________ ___ __________.
_____ ___ ___ _____ ____ _________ ____ _______ ___.
_______ _______ _______ ______ _________.
__________ ______ ____ ___ __________ ________ _____ __________ _____ ________ ______ _______.
_______ ________ ______ ___ _____.
________ __________ __________ _____ ________ ___ _______ ______ __________ ____.
_______ _______ __________ ______ _________ ____ _________.
_________ _________ ____ ________ __________ ____ ________ ____ ___ _____.
_______ __________ ___ _________ ______ ___ ____ ________ _____ ______ ______.
_____ _____ _____ _________ ____ ________ _____ _______ _______ ________ ______ _______.
__________ _________ ________ _____ __________ __________ ___.
___ __________ ____ ________ ______ _________ ______ ____ _______.
__________ ________ ___ ________ __________.
___ ________ ____ ________ ________ _______ ______ __________ ________ ____ _______ _______.
____ _______ _____ ____ ___ ____ _____ ________ ______ _________ __________.
______ _______ _______ _______ ________ _________ __________ ___ ______ ___.
___ _______ ____ ______ __________ _________ _________ _________.
____ _______ ______ ________ _____ ________ _______ ____ ______ _____ _______ _______.
________ __________ _________ ______ _________.
_________ ________ __________ ______ ___.
_____ ___ ________ __________ ________ ____ _________ __________ ______ ____ ________ ____.
__________ ___ _____ _________ ____ ______ _________ _________ ____.
___ ____ __________ ____ _____ _______ ______.
___ ___ ______ ________ ____.