NSF International shares food safety tips from time to time, and when it’s right before a holiday when I know there will be a lot of parties where food will be left out on tables for several hours, in or out of the sun, I like to pass the tips along.

If you’re hosting a Memorial Day gathering this weekend, make sure to heed the following summer food safety tips.

Tip #1: Start with a clean kitchen

In testing products for NSF International’s Home Product Certification Program, NSF microbiologists found that appliances and utensils with lots of crevices provide ideal environments for moisture to gather and germs to grow. Some of the germiest places in a kitchen are the refrigerator meat and vegetable compartment, blender gasket, can opener, rubber spatula and the rubber seals on food storage containers.

Tip #2: Store and defrost foods safely

Always bring perishable foods straight home from the store and place them in the refrigerator or freezer. If frozen, foods can be thawed either in the microwave (if cooking immediately) or overnight in the refrigerator. Never leave food out at room temperature to thaw.

Make sure to regularly clean and dry your refrigerator’s meat and vegetable compartments thoroughly with warm soapy water and a clean towel, as they can often house bacteria such as salmonella, E. coli, yeast and mold, which can cross-contaminate other foods. What many people may not realize is that the types of germs found in these areas were harmful (such as E. coli and salmonella) and come into direct contact with food, especially raw produce. What we learned is that 1) it isn’t enough to wash your produce. You must also wash the areas where the produce is stored, and 2) storing clean and unwashed produce together can be problematic.

Note: Most frozen meats can be cooked from the frozen state, but will usually take up to 50 percent longer to cook.

Tip #3: Keep hot foods hot and cold foods cold

Since bacteria grow the quickest when temperatures are between 40º F and 140º F, keep perishable foods refrigerated or iced down until just before placing on a preheated grill or serving, and keep hot foods above 140º F once fully cooked.

Tip #4: Avoid cross contamination

Bacteria can easily spread from one food to the next via dripping juices, hands, or utensils. Prior to cooking, be sure all utensils are cleaned according to the manufacturer’s instructions. Don’t use the same utensils and plates for raw or uncooked foods as you do for cooked foods.

Tip #5: Cook with a thermometer, not your eyes

Always use a certified food thermometer to make sure foods are cooked to the proper minimum internal temperature, inserting into the thickest part of the meat:

• Whole or ground poultry — 165º F
• Ground meats (other than poultry) — 160º F
• Fresh fin fish — 145º F
• Fresh whole (not ground) pork, beef, veal — 145º F with a 3-minute rest time

Rest time refers to the amount of time the meat needs to stand without carving once it’s reached a minimum safe cooking temperature.

Tip #6: Pack perishable foods properly

Put perishable foods such as hot dogs, cut fruits and salads in individual containers and place on the bottom of the cooler with ice packs on top. This provides the best insulation for foods that need to remain cool and helps prevent cross contamination.

To clean dishwasher-safe containers with rubber seals, place both the container and the lid in the dishwasher and wash after each use. If hand washing, wash both the container and lid in hot soapy water, paying special attention to the area around the seal as well as any grooves where the cover attaches to the container. Rinse thoroughly and allow to air dry.

Tip #7: Transport foods safely

To avoid contamination while traveling with food, transport uncooked meats in a separate cooler from ready-to-eat foods. During hot summer months, put the coolers in the air conditioned back seat of the car instead of the hot trunk. When you arrive at your destination, you’ll also want to put drinks in a separate cooler to avoid frequent opening of a container with perishable foods — this lowers the temperature and makes the food inside more susceptible to bacterial growth.

Tip #8: Don’t prepare food more than a day in advance unless it is to be frozen

Cooking foods in advance allows for more opportunities for bacteria to grow. It’s best to cook foods thoroughly just before eating them. If you have to cook foods more than a day in advance, be sure to reheat pre-cooked foods to at least 165º F before serving.

Tip #9: Remember the 1-hour rule

Don’t consume perishable foods that have been sitting out beyond an hour on days where the temperature is over 90º F. On cooler days, perishable foods should be returned to the cooler or discarded if not eaten within two hours. For this reason, you’ll want to throw out most leftovers, especially if you’ve been outdoors for an extended period of time.

More food safety tips, information on the 2013 germ study findings, and the importance of following kitchen tool and appliance cleaning instructions are located at: www.nsf.org/consumer.

Related safety tips on MNN:

The opinions expressed by MNN Bloggers and those providing comments are theirs alone, and do not reflect the opinions of MNN.com. While we have reviewed their content to make sure it complies with our Terms and Conditions, MNN is not responsible for the accuracy of any of their information.