Food Safety

Purdue University

Cooperative Extension Service

West Lafayette, IN 47907

Keeping Food Safe During Emergencies

Jo Carol Chezem, R.D., Graduate Extension Assistant,
Wilella Daniels Burgess and April C. Mason, Extension Specialists,
Department of Foods and Nutrition,
School of Consumer and Family Sciences

Disasters can come in many forms, including tornados, fires, floods, and snowstorms. In any of these emergency situations, two problems commonly arise. The first is a lack of incoming supplies. The second is damage to gas and electrical power systems. This publication discusses how to handle foods before, during, and after an emergency to keep them safe and to avoid food poisoning.

How Do I Plan an Emergency Food Supply?

Frequently, emergencies arise with little or no warning. To insure an adequate diet during an emergency, keep on hand a week's supply of food that does not need refrigeration. Table 1 lists a variety of foods which can be safely stored at room temperature. Choose food based on the special needs and preferences of your family. For example, if your household includes an infant, you may need a supply of formula or food that can be easily strained or chopped. In addition to food, it's important to keep extra essential medications and supplies.

Another factor to consider when choosing emergency food is the ease of preparation. Select food that can be quickly warmed or eaten cold. Canned - goods are often a wise choice; the can serves as both cooking pot and serving dish. Dried beans are generally a poor choice. Although they are easy to store, they are not so easy to prepare.

Consider storage conditions and length of storage when planning an emergency food supply. Ideally, store food in a cool dry place at temperatures between 40F and 70F. Although canned and dehydrated food will still be safe after one year, time may reduce quality and nutritional value. For this reason, you should occasionally use stockpiled food for regular meals and purchase new items to replace it.

How Do I Prepare Food with No Power?

During an emergency, cooking and eating habits must change to fit the situation. You may have no refrigeration, no stove, and limited water. In addition, health risks from contaminated or spoiled food may increase. When preparing food, consider the following:

1. The amount of cooking time needed for a particular food. If there is limited fuel for cooking, choose food which cooks quickly or serve no-cook food.

Table 1: Assembling and Emergency Food Supply

Food Group             Amount per Person                     Suggested Foods
                           per day   
Milk                     2 cups(reconstituted)     Evaporated canned milk; powdered milk
Vegetables               2 servings                 canned vegetables; canned vegetable juice
Fruit                    2-4 servings               canned fruit; canned juice; dried fruit
Meat, poultry,           2-3 servings               canned meat, poultry, and fish;
 fish, dry beans,                                   canned meat mixtures; canned or dried beans;
eggs, and nuts                                      canned soups containing meat or beans; dried
                                                    meat (beef jerky); peanut butter; nuts
Bread. cereal.           6-11 servings              ready-to-eat cereal; instant hot cereal;
 rice, and pasta                                     minute rice; crackers;
                                                    canned spaghetti; canned soup containing
                                                    noodles or rice
Fats, oils. and          according to family
 sweets                  practices
Miscellaneous            according to family        coffee, tea, cocoa,
                         practices                  powdered beverages, soft drink

2. The amount of food to prepare. If refrigeration is not available, prepare only the amount of food you need for one meal and discard any perishable leftovers. When left at room temperature, milk, meat, soups, pasta, legumes, and vegetables provide excellent growing conditions for microorganisms which cause food poisoning.

3. The cooking methods available. These include:

Is My Water Safe?

A disaster may disrupt the electricity needed to pump water in the home and/or contaminate the water supply. Planning ahead can assure there is enough safe water for drinking, preparing food, brushing teeth, and keeping clean.

You can store water ahead for use in emergencies. Boiled water, stored in sterilized containers will keep for six months to one year. While the water may taste flat, it is safe to drink or use in cooking.

Your hot water heater or water pressure tank could supply many gallons of safe water during an emergency. Before using water from the water heater, switch off the gas or electricity which heats the water. Leaving the power on while the heater is empty could cause an explosion or burn out the elements. After turning off the power source, open the drain valve at the bottom of the tank. Do not turn the water heater on again until the water system is back in service.

Unless you are absolutely certain your water supply is not contaminated, purify all water before using it for drinking, preparing food, brushing teeth, or washing dishes. If the water contains sediment or floating material, strain it through a cloth before purifying it. If you have access to heat or power, water can be made safe by boiling; if not, you will have to treat it with chemicals.


Boil water at a rolling boil for ten minutes to kill any disease-causing bacteria. Add a pinch of salt to each quart of boiled water to improve the taste.

Chemical treatment:

Any of the following three (3) chemical treatments will purify water.

1)Chlorine bleach. Household bleach is a good disinfectant for water. Before using, check the label to be sure hypochlorite is the only active ingredient in the bleach. Do not use bleach that contains soap. Since the amount of chlorine in bleach is variable, use the following table to determine the appropriate amount needed to purify water. Mix the bleach thoroughly in the water and let it stand for 30 minutes. The water should have a slight chlorine odor. If it doesn't, repeat the dose and let the water stand for an additional 15 minutes.

             Percent     Add per
             chlorine    gallon water
             1%          40 drops
             2 to 6%      8 drops
             7to10%       4drops
             unknown     10 drops

2) Iodine. Household iodine from the medicine cabinet will purify water. The iodine should be 2% United States Pharmacopeia (U.S.P.) strength. Add 20 drops per gallon of clear water and 40 drops per gallon of cloudy water.

3) Water purification tablets. Water purification tablets will also purify water. These tablets are available at drug stores. Follow the manufacturer's instructions.

What Do I Do When the Refrigerator and Freezer Stop?

Most home refrigerators and freezers stop running at least once during their lifetimes. Whether due to a power outage or a broken appliance, a power failure brings with it the risk of food spoilage.

Bacteria are present all around us -on our bodies, in food, and on cooking utensils. In small amounts, these bacteria are harmless. In large numbers, these bacteria may cause food poisoning. At temperatures below freezing, most bacteria that cause foodborne illness survive, but do not grow. Refrigeration at 40F or below allows only slow growth of bacteria. As the storage temperature of perishable food rises above 40F, the rate of bacterial growth increases. After these foods are left more than two hours above 40F, there is a strong chance that the number of bacteria has risen to a level which can cause food poisoning. The information below will help you keep food safe longer and evaluate the safety of foods affected by a power failure.

How do I keep my food frozen?

0nce the freezer fails, the length of time food in it will stay frozen depends on:

As soon as you discover a freezer failure, call the utility company to find out when power might be restored or the appliance repair service to find Out when the freezer can be worked on. If there is a chance the freezer will be out of service for some time, you may need to take steps to prevent food loss.

Make plans with a local meat locker plant before an emergency arises. If freezer failure occurs, call the locker plant to see if it is open and has room for your food. During transport to the locker, insulate the food by wrapping it in newspapers or blankets.

If there is no locker space and the freezer will be without power for more than one day, dry ice may be helpful. The more dry ice you use, the longer the food will stay frozen. Twenty-five pounds of dry ice added soon after a power loss should keep the food in a half-full, medium-sized (10-cubic-foot) freezer frozen for two to three days. In a full freezer of the same size, twenty-five pounds of dry ice should keep foods frozen for three to four days. Place the dry ice on a piece of cardboard on top of the food packages. To protect your skin, always wear gloves when handling dry ice.

Finding a source of dry ice may take a little work. Check the yellow pages under "dry ice." Call local dairies, cold storage warehouses, or other businesses that might use dry ice.

0ther tips to reduce loss of frozen food include:

Table 2: Evaluating Freezer Foods

                 Partially frozen-         Completely thawed       Completely thawed
                 some ice crystals            -still cold              -warm
                                              (below 400F)           (above 40F)
   beef                                      cook and serve
   veal            refreeze                        or               discard  
   lamb                                     cook and refreeze

   poultry         refreeze                   cook and serve        discard
                                           or cook and refreeze

 organ meats       use within 48             cook and serve         discard
   liver               hours;
   kidney          do not refreeze

fish and shellfish   refreeze                cook and serve        discard
                                         or cook and refreeze
combination dishes  cook and serve           cook and serve        discard
   stews                or
   casseroles      cook and refreeze*
   meat pies                                                

dairy items         refreeze                  refreeze             discard
   cream                                          or
   cheese                                     refrigerate

produce            refreeze                 cook and serve        discard
juices             refreeze                  refreeze              discard

baked goods                           
   bread           refreeze                  refreeze              serve
   fruit pies      refreeze                  refreeze              discard
   plain cakes     refreeze                  refreeze              serve
 *Refreeze only those dishes containing raw ingredients.  
Do not refreeze previously cooked dishes.

How do I keep my refrigerated food cold?

Food will remain chilled for four to six hours in a refrigerator without power. To keep temperatures cool longer, add bags of regular ice. Place the ice on upper shelves and pans to catch the melting ice on lower shelves. The more ice you use, the longer the temperature will stay cool. Open the door only to add ice. Place a thermometer in the area furthest from the ice. Check the refrigerator temperature when adding ice and as soon as the power returns to be sure that food has been kept below 40F.

Is my food still safe?

Once your freezer and/or refrigerator are working again, evaluate the safety of the affected food. For frozen food, consider the type of food and the extent of thawing. For refrigerated food, consider the temperature inside the refrigerator before the return of power, the type of food, and the time these foods have been stored above 40F. Use Tables 2 and 3 when deciding which foods may safely be kept and which ones should be thrown out. Remember, when in doubt, throw it out.

Table 3: Evaluating Refrigerated Foods

Milk                          Discard if held above 40F over two hours.

Fruit juices                  Generally safe unrefrigerated until power returns, but discard if cloudy,
                              moldy, or fermented.

Eggs  fresh or hard-boiled    Discard if held above 40F over two hours.

Hard cheeses, butter, margarine Generally safe unrefrigerated if well-wrapped, but discard if mold or
                              rancid odor develops.

Fresh fruits and vegetables   Generally safe unrefrigerated until power returns, but discard if mold,
                              yeasty odor, or slimy texture develops.

Fresh meats and poultry       Discard if held above 40F over two hours.
Lunch meats and hot dogs      Discard if held above 40F over two hours.
Mayonnaise (opened)           Discard if held above 40F over two hours.

Opened containers of jelly,   Safe unrefrigerated until power returns.
jam, mustard, ketchup, pickles.
and olives

How do I get rid of odors?

Strong food odors may develop as a result of food spoilage during a power failure. Because the refrigerator or freezer must be empty and unplugged when cleaning, the best time to combat these odors is before restocking foods. Below are some ideas for removing unwanted odors:

Is Food That Has Been in a Flood Safe?

Flood waters may carry silt, raw sewage, oil, or chemical waste. Being prepared is the key to keeping food safe during a flood. Prevent flood water from coming into contact with food by:

Once food has come into contact with flood waters, use the following chart to determine its safety.



Instructions for sanitizing flooded canned foods

You must also sanitize dishes and cookware that have come into contact with flood waters. Treat dishes and glassware using the instructions for canned goods. Disinfect metal pans and utensils by boiling them in water 10 minutes. Discard and replace wooden spoons, plastic utensils, and baby bottles.

Can I Eat Food That Has Been in a Fire?

Fires can seriously compromise the safety of food. Three factors can affect food that has been exposed to fire-the heat of the fire, smoke fumes, and chemicals used to fight the fire. Food in cans or jars may seem "okay," but may, in fact, be inedible since high temperatures can activate food spoilage bacteria. One of the most dangerous elements of a fire is the toxic fumes released from burning materials. These fumes can contaminate food. Chemicals used to fight fires also contain toxic materials and can contaminate food and cookware. Below are some guidelines for checking the safety of food after a fire:

Where Can I Get Additional Information?

While most people think natural disasters will never strike them, over 800,000 Americans are affected by such catastrophes each year. Loss of electrical power and refrigeration, as well as chemical and bacterial contamination, can jeopardize food and put people at risk for food poisoning. If you have additional questions on how to safely store food before an emergency and how to handle food safely during and after an emergency, please contact your county's Cooperative Extension Office.


RR 11/94

Cooperative Extension work in Agriculture and Home Economics, State of Indiana, Purdue University and U.S. Department of Agriculture cooperating: H.A. Wadsworth, Director, West Lafayette, IN. Issued in furtherance of the acts of May 8 and June 30, 1914. The Cooperative Extension Service of Purdue University is an equal opportunity/equal access institution.