Contamination:
Contamination is the presence of a minor and unwanted constituent (contaminant) in a material, in a physical body, in the natural environment, at a workplace.
Contamination Control Procedure
The following is a sample procedure for the control and decontamination of radioisotope work areas. Your procedure may vary but should include all the requirements to insuring the safe and controlled use of radioisotopes and the area there are area in.
Radioisotope Usage Area.
The area in which radioisotopes are to be used should have the following: * Isolated from general lab personnel * Proper signage * Spillage control * Map of work area (to be used for wipe tests) * Log books. * Proper apparel and gloves.
Wipe Test Procedure: * Work Area Map * Wipe test Worksheet * Wipe areas on concern (10cm x 10cm) * Log results * File worksheet
Decontamination Procedures: * Wipe Test Map * Clean area of concern with appropriate decontaminating solution. * Perform a new wipe test. * Clean area again if needed. * Log results * File worksheet http://cset.mnsu.edu/radiationsafety/Documents%20and%20Forms/Contamination%20Control%20Procedure.pdf Cross Contamination:
Cross-contamination is the physical movement or transfer of harmful bacteria from one person, object or place to another.
Preventing Cross Contamination:
When shopping: * Separate raw meat, poultry, and seafood from other foods in your grocery-shopping cart. * Place these foods in plastic bags to prevent their juices from dripping onto other foods. * It is also best to separate these foods from other foods at check out and in your grocery bags.

When refrigerating food: * Place raw meat, poultry, and seafood in containers or sealed plastic bags to prevent their juices from dripping onto other foods. Raw juices often contain harmful bacteria. * Store eggs in their original carton and refrigerate as soon as possible.

When preparing food:
Keep it clean: * Wash hands and surfaces often. Harmful bacteria can spread throughout the kitchen and get onto cutting boards, utensils, and counter tops. To prevent this: * Wash hands with soap and hot water before and after handling food, and after using the bathroom, changing diapers; or handling pets. * Use hot, soapy water and paper towels or clean cloths to wipe up kitchen surfaces or spills. Wash cloths often in the hot cycle of your washing machine. * Wash cutting boards, dishes, and counter tops with hot, soapy water after preparing each food item and before you go on to the next item

Cutting boards: * Always use a clean cutting board. * If possible, use one cutting board for fresh produce and a separate one for raw meat, poultry, and seafood. * Once cutting boards become excessively worn or develop hard-to-clean grooves, you should replace them.

Marinating food: * Always marinate food in the refrigerator, not on the counter. * Sauce that is used to marinate raw meat, poultry, or seafood should not be used on cooked foods, unless it is boiled just before using.

Fruits and vegetables: * Rinse fresh fruits and vegetables in running tap water to remove visible dirt and grime. * Remove and discard the outermost leaves of a head of lettuce or cabbage. * Because bacteria can grow well on the cut surface of fruit or vegetables, be careful not to contaminate these foods while slicing them up on the cutting board, and avoid leaving cut produce at room temperature for many hours.

When serving food: * Always use a clean plate. * Never place cooked food back on the same plate or cutting board that previously held raw food.

http://www.health.state.mn.us/foodsafety/clean/xcontamination.html

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http://www.qualityassurancemag.com/qa0213-doorway-sanitizers-use.aspx