The Medical Minute: Picnic safety

May 25, 2005

By: John Messmer
Penn State Family & Community Medicine
Penn State Milton S. Hershey Medical Center
Penn State College of Medicine

Memorial Day marks the start of the season of picnics and backyard barbecues. Cooking outside means a little more care in food handling to avoid food borne illness. Fortunately, illness from food is on the decline according to the Centers for Disease Control. To help continue this trend, it's a good idea to review some pointers about safe food handling.

Meats should be kept cold -- 40 degrees, which is refrigerator temperature -- until cooked. This keeps the bacteria found on all fresh meats from growing. Thaw frozen meat in the refrigerator so it stays cool. If the meat is brought outside, keep it in an ice chest until grilling begins, and do not put other foods into the same cooler. Wash hands before and after handling raw meat. Take care to wash particularly before serving food to avoid contamination. If marinating meat, do it in the refrigerator to keep it cold. Do not baste the meat with the marinade -- reserve some marinade that does not touch the raw meat to use for basting. Any uneaten meat should be refrigerated by one hour after cooking.

Meat must be cooked to the proper temperature, particularly hamburger, which should be cooked completely. Bacteria in most meat are on the outside so it is relatively safe to eat beef rare. When hamburger is made, any bacteria found on the outside is mixed throughout the meat, so avoid pink color in hamburger or use a thermometer to see that it has reached the recommended temperature of 160 degrees. Chicken should be 175 degrees, pork 160 degrees and all other meats 145 degrees. Keep the meat warm at 140 degrees or more on a warmer rack on the grill or in a 200 degree oven. Reheated meat should be 165 degrees.

Remember to use clean utensils. Utensils that touch raw meat should not be used to handle cooked foods until washed thoroughly. Eating surfaces should be clean or covered with clean tablecloths or similar material. Wash preparation surfaces with soap.

Eggs sometimes carry bacteria, typically Salmonella. Fortunately thorough cooking kills these bacteria. Although healthy peoples' immune systems usually eliminate Salmonella, the illness can be unpleasant. Infants and the elderly and those with chronic health problems are particularly susceptible to injury. Be sure to cook eggs through and keep them refrigerated before and after cooking. Harmful bacteria may not cause odor so do not depend on smell to identify infected food.

Mayonnaise and milk must stay cold at all times. Eggs and mayonnaise that have warmed should be thrown out. Milk can stay fresh ten days at 40 degrees, but only a day or so if it reaches room temperature. Keep cold foods in the cooler until ready to use and return them to the cooler in less than one hour.

Symptoms of food-borne illness begin from hours to as much as a week from getting the infection. Most healthy people will do well but infants, the elderly and those with chronic health problems should contact their doctors if they develop vomiting or diarrhea within a week or so of eating potentially contaminated foods.

More information on food-borne illness is available at and More details on picnic safety is available from the USDA at online.

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Last Updated March 19, 2009