CAUSES AND PREVENTION OF FOODBORNE ILLNESS
Food Safety Education Program http://web.uri.edu/foodsafety
FOODBORNE ILLNESS STATISTICS MICROBIOLOGY OF FOODBORNE ILLNESS
CDC estimates roughly 1 in 6 Americans (48 million Bacteria are single-celled organisms which multiply by people) get sick, 128,000 are hospitalized, and 3,000 die cell division, under appropriate environmental conditions. of foodborne diseases each year. Symptoms of food- The conditions that influence bacterial growth are the borne illness include upset stomach, abdominal cramps, food itself, acidity, time, temperature, oxygen, and mois- nausea, vomiting, diarrhea, fever, and dehydration; they ture. Most bacteria need nutrients to survive. They obtain can range from mild to severe and death. these nutrients from food. Bacteria grow best in food that Foodborne illness can affect anyone who eats con- is neutral to slightly acidic (acidity is measured by pH). Mi- taminated food; however, certain populations are more croorganisms have different acidity (pH), temperature, susceptible to becoming ill with a greater severity of ill- and oxygen requirements for optimal growth. Bacteria ness. These populations include infants and children, the need time to grow and they grow rapidly between 41°F elderly, pregnant women, people taking certain kinds of and 140°F. Bacterial growth is slowed at temperatures medications or immune suppressed (e.g., cancer pa- below 41°F and limited at temperatures above 140°F. tients, diabetics). Some bacteria require oxygen to grow (aerobic), some To prevent foodborne illness, it is necessary to un- grow when there is no oxygen (anaerobic), and some can derstand how food becomes unsafe to eat and what pro- grow with or without oxygen (facultative). Bacteria will active measures can be taken to keep food safe. grow when food and water is available. If water is bound or tied up with, for example salts or sugars, it is not availa- CAUSES OF FOODBORNE ILLNESS ble to be used by bacteria. This concept of available water is referred to as water activity (Aw). The causes fall into the following 3 categories: Biological hazards include bacteria, viruses, and par- Some bacteria can be further categorized: asites. Bacteria and viruses are responsible for most Some bacteria are spore formers. The spore pro- foodborne illnesses. Biological hazards are the big- tects the organism during periods of environmental gest threat to food safety. They can be inherent in stress. When the conditions become suitable, the the product or due to mishandling (e.g., time/ organism germinates from the spore and continues temperature abuse). the growth cycle. Chemical hazards include natural toxins and chemi- Some bacteria produce toxins that cause illness. cal contaminants. Some natural toxins are associated with the food itself (i.e., certain mushrooms, PSP in Molds are a multi-cellular fungi that reproduce by molluscan shellfish), some are made by pathogens in fruiting bodies that break and release thousands of mi- the food when it is time/temperature abused (i.e., croscopic mold spores, each capable of growing under histamine development in certain seafood species). the right conditions. Molds can send “roots” into the food Some additives, such as sulfites, can be a hazard to to provide nourishment to the spore. Molds prefer damp, some people. Chemical contamination can occur dark environments for optimal growth and they grow when products (i.e., cleaners) are not used correctly. readily on almost any food, as well as walls, ceilings, and Food allergens are a chemical hazard. Some other areas of high moisture. Some molds produce toxins people are sensitive to proteins in foods. Every that can cause illness.
food is different. Eight major food allergens Viruses are the smallest known organisms. They can- include milk, eggs, fish, crustacean shellfish not multiply in food—they need a human host. Viruses (lobster, crab, shrimp), wheat, soy, peanuts, are transmitted to food from infected people. tree nuts. Physical hazards can include metal shavings from Parasites include worms and protozoa. They cannot cans and plastic pieces or broken glass. multiply in food; they multiply in a host cell.
The University of Rhode Island is and equal opportunity employer committed to community, equity, and diversity and to the principles of affirmative action. 1 Updated 12/2016
CAUSES AND PREVENTION OF FOODBORNE ILLNESS
Food Safety Education Program http://web.uri.edu/foodsafety
TYPES OF FOODBORNE ILLNESS To sanitize for added protection for bacteria on surfaces, you can use the following: Pathogens can cause different types of foodborne illness. Once a contaminated food is eaten, illness can be Dilute mixtures of chlorine bleach and water caused by the pathogens themselves (foodborne infec- are a cost-effective method of sanitation. tion); caused by toxins produced in the food by patho- Chlorine bleach is a very effective sanitizer. It gens (foodborne intoxication); and caused by toxins comes in several concentrations. produced in the body by pathogens (foodborne toxin- If bleach is 8.25%: measure 1 teaspoon of mediated infection). bleach per 1 gallon of water or 1/8 teaspoon of bleach per 1 pint of water. PREVENTION OF FOODBORNE ILLNESS Apply to the cleaned countertop and allow to sit for 1-2 minutes and air dry or dry with a Follow these 4 simple steps to keep food safe: clean paper towel. CLEAN: Wash hands and food contact surfaces and uten- Alternatively, commercial products for sanitiz- sils often, between tasks, and if they have become con- ing the home kitchen are available. Follow taminated. Effective cleaning involves removing soil and manufacturer instruction for use. debris, scrubbing with hot soapy water and rinsing, us- Wash dish cloths often in a washing machine. ing potable/drinking water. Sanitizing involves the use of Store sponge in a place so it can dry after use. high heat (e.g., a dishwasher) or chemicals (e.g., chlorine To lower the risk of cross-contamination, sani- bleach) to reduce or eliminate the number of microor- tize the dish sponge often: ganisms to a safe level. Soak in a chlorine bleach solution for 1 min.
Wash hands with warm water and soap for 20 sec- See the following link on instructions for the onds and dry with a disposable paper towel or bleach solution: http://msue.anr.msu.edu/ clean hand cloth. news/sanitizing_kitchen_sponges Alcohol based hand sanitizers are not a re- Microwave heat a damp sponge for 1 min. placement for handwashing. They are not Put sponge in dishwasher cycle. effective if the hands are dirty, they are not Replace the dish sponge often. effective against Norovirus, and they do not eliminate all types of microorganisms. SEPARATE to prevent cross contamination. Cross contam- ination is the transfer of harmful bacteria from uncooked Wash cutting boards, dishes, and utensils after pre- food products (e.g. raw meat, fish, and poultry) or un- paring each food item and before you use it for the clean people, countertops, and kitchen equipment to next food. ready-to-eat foods (e.g., fruits, vegetables, deli meats/ Use hot, soapy water, rinse with hot water, cheeses, and prepared or cooked foods). and air dry or dry with a clean paper towel or clean dish cloth. Prevent cross contamination when grocery shopping. Or wash in the dishwasher. Physically separate raw meat, fish and poultry
Wash countertops after preparing each food item to prevent their juices from dripping onto other and before you use it for the next food. foods. This can be done by: Use paper towels or clean dish cloths to wipe Segregating raw meat, fish and poultry on one kitchen surfaces or spills. side of the shopping cart. Wash countertops with hot soapy water, rinse Placing raw meat, fish and poultry in separate with hot water and air dry or dry with a clean plastic bags (e.g. one bag for chicken, one bag paper towel or clean dish cloth. for fish, etc.).
The University of Rhode Island is and equal opportunity employer committed to community, equity, and diversity and to the principles of affirmative action. 2 Updated 12/2016
CAUSES AND PREVENTION OF FOODBORNE ILLNESS
Food Safety Education Program http://web.uri.edu/foodsafety
Designate reusable bags for grocery shopping only. Throw away any sauce or dip that has been Reusable bags for raw meat, fish, or poultry should used to marinade raw meat, fish, or poultry. never be used for ready-to-eat products. Do not use this extra sauce as a dip for Frequently wash bags. Cloth bags should be cooked food unless it is boiled first. washed in a machine and machine dried or air -dried. Plastic-lined bags should be scrubbed COOK food thoroughly and use a thermometer to verify using hot water and soap and air-dried. the proper temperature was reached. Separate raw meat, fish and poultry in dispos- Cook foods to the safe minimum internal tempera- able plastic bags before putting them in a re- ture, as indicated in the table below: usable bag Product Minimum Internal Temperature Check that both cloth and plastic-lined reusa- ble bags are completely dry before storing. Beef, Pork, Veal & Lamb 145 °F (62.8 °C) and allow to rest for at steaks, chops, roasts least 3 minutes Prevent cross contamination when storing food in the refrigerator. Ground Meats 160 °F (71.1 °C) In the refrigerator, store raw meats, fish, and Ham, fresh or smoked 145 °F (62.8 °C) and rest for at least 3 poultry below ready-to-eat and cooked foods. (uncooked) min. When thawing frozen raw meat, fish and Fully Cooked Ham Reheat cooked hams packaged in USDA- poultry, put the food in a plastic bag or on a (to reheat) inspected plants to 140 °F (60 °C); plate on the lowest shelf to prevent juices from dripping onto other foods. All Poultry (breasts, whole, 165 °F (73.9 °C) legs, thighs, wings, ground, and After thawing in the refrigerator, food should remain safe and of good quality for a few days before cooking. Food Eggs 160 °F (71.1 °C) thawed in the refrigerator can be refro- Fish & Shellfish 145 °F (62.8 °C) zen without cooking, although quality Leftovers 165 °F (73.9 °C) may be impacted. See Chill section for Casseroles 165 °F (73.9 °C) other methods for thawing. Prevent cross contamination when handling, pre- USDA FSIS Safe Minimum Internal Temperature Chart www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/ paring, and serving food. safe-food-handling/safe-minimum-internal-temperature-chart/ct_index Thoroughly wash your hands before and after handling different foods, after using the bath- To determine that the proper temperature was room, and anytime they can become contami- reached, place a food thermometer in the thickest nated. part of the food and allow the it to equilibrate. Use separate cutting boards for meat and pro- Make sure it’s not touching bone, fat, or gristle. duce. Alternatively, prepare produce first, For whole poultry, insert the thermometer into then meat. the innermost part of the thigh and wing and Wash and rinse cutting board, knives, and the thickest part of the breast. preparation area after cutting raw meat, fish For combination dishes, place the thermome- or poultry. These items can be sanitized after ter in the center or thickest portion. cleaning. Egg dishes and dishes containing ground meat Use a clean serving plate to serve cooked or poultry should be checked in several places. meat. Do not use the plate that held the raw Clean your food thermometer with hot, soapy water meat, unless it is washed. before and after each use!
The University of Rhode Island is and equal opportunity employer committed to community, equity, and diversity and to the principles of affirmative action. 3 Updated 12/2016
CAUSES AND PREVENTION OF FOODBORNE ILLNESS
Food Safety Education Program http://web.uri.edu/foodsafety
Food Thermometers – Why use them? Not only is it im- in the refrigerator or freezer (one hour when the portant to monitor the refrigerator temperature (chill temperature is above 90°F). foods); but using a thermometer is the only reliable way There are three safe ways to thaw food: in the re- to ensure that a food is properly cooked. When cooking: frigerator (see Separate), in cold water, and in the Color is not a reliable indicator that the food has been microwave. Food thawed in cold water or in the cooked to the correct temperature to ensure that microwave should be cooked immediately and prior foodborne pathogens are destroyed. to refreezing. Determining “doneness” of hamburger cannot be Submerging the food in cold water. It is im- safely done by looking at the brown color of the meat portant to place the food in an impermeable or of chicken by looking that the juices run clear. bag. Check the water every 30 minutes to Time alone as an indicator that the food is cooked make sure it is cold. properly could result in a potential food safety haz- Microwave thawing. Cook food immediately ard. Recipes may state “x minutes/pound”. However, once thawed because some areas of the food different thicknesses of a food or ingredients that are may warm and begin to cook. used can alter the time needed at a specific tempera- Cool leftovers quickly by dividing large amounts into ture to make sure the food has reached the correct shallow containers in the refrigerator. temperature to kill all pathogens. Food thermometers come in several types and styles Resources Used and for More Information:
and range in level of technology and price. There is a CDC’s Food Safety Website: www.cdc.gov/foodsafety lot of good information on how to use a thermometer FDA Food Safety Resources for Consumers correctly, proper placement, and how to check to see www.fda.gov/Food/ResourcesForYou/Consumers/ if it is accurate (see Resources– Thermometers). ucm077286.htm Pop-up temperature devices are commonly found in FDA Refrigerator Thermometers: Cold Facts about Food Safety turkeys or oven roaster chickens. These devices indi- cate that the food has come to the correct tempera- www.fda.gov/food/foodborneillnesscontaminants/ buystoreservesafefood/ucm253954.htm#strat ture for safety. However, while these devices are reli- able, it is recommended that the temperature be Gateway to Federal Food Safety Information: Foodsafety.gov checked in several places with a conventional ther- Partnership for Food Safety Education: Fightbac.org mometer to ensure proper cooking. USDA’s Food Safety Fact Sheets CHILL foods promptly. Cold temperatures slow the www.fsis.usda.gov/wps/portal/fsis/topics/food-safety- growth of harmful bacteria. Cold air must circulate to education/get-answers/food-safety-fact-sheets help keep food safe, so do not over fill the refrigerator. USDA’s Safe Food Cooking Temperature Chart Maintain the refrigerator temperature at 41°F or below. www.fsis.usda.gov/wps/portal/fsis/topics/food-safety- Place an appliance thermometer in the rear portion of education/get-answers/food-safety-fact-sheets/safe-food- the refrigerator, and monitor regularly. Maintain the handling/safe-minimum-internal-temperature-chart/ct_index freezer temperature at 0°F or below. Refrigerate and freeze meat, poultry, eggs and oth- Thermometers www.fsis.usda.gov/wps/portal/fsis/topics/food-safety- er perishables as soon as possible after purchasing. education/get-answers/food-safety-fact-sheets/appliances-and- Consider using a cooler with ice or gel packs thermometers to transport perishable food. www.fsis.usda.gov/wps/portal/fsis/topics/food-safety- Perishable foods, such as cut fresh fruits or vegeta- education/teach-others/fsis-educational-campaigns/thermy/ bles and cooked food should not sit at room tem- thermometers-and-food-safety/ct_index perature more than two hours before putting them www.foodsafety.gov/keep/basics/cook/thermometers.html
The University of Rhode Island is and equal opportunity employer committed to community, equity, and diversity and to the principles of affirmative action. 4 Updated 12/2016