It depends on the food. Potentially hazardous food (eggs, milk, meat, chicken, fish, etc.) should not be unrefrigerated for more than 2 hours, but less time is better. Butter and margarine and many condiments will be OK for a longer period of time. When in doubt, throw it out.
Milk
1. How long after the "sell by" date is an opened container of milk good?
2. How long after the "sell by" date is an UNOPENED container of milk good?
Sell date indicates the final date the product should be sold. It allows for storage time at home. Examples of products that display sell dates are refrigerated dough products, luncheon meats and milk. This is the last day that the product can be sold in the grocery store.
Recommend storing milk between 34° F and 38° F: Milk stays fresh and tastes best longest at these temperatures, and will often be of good quality beyond the sell-date if maintained cold. Much depends on how a product was handled before you bought it. Milk past its sell-date may still be fine if it's been kept very cold. At warmer temperatures, spoilage bacteria are more likely to grow, shortening the practical shelf-life of the product. Always return unused containers or portions of milk promptly to the refrigerator.
Buy milk fresh, keep it cold and protect It from light. Though properly held milk should still be acceptable beyond the code date, milk does not improve with age and will not be as fresh tasting. Unopened containers of food can be kept longer than opened containers. Opened containers of milk can be stored in the refrigerator for 1 week after they have been opened. Be sure to check the date on the carton.
Beer
Unopened: Starts to lose flavor after 110 days.
It's best to store bottles in boxes, and then in dark place.
Stronger alcohol and higher levels of hops might extend the shelf life of a beer.
One example is Michelob Craft Specialty beers, which are often at their peak with 180 days.
(Source: Budweiser support)
Brown sugar
Indefinite shelf life, stored in a moisture proof container in a cool, dry place.
Chocolate (Hershey bar)
1 year from production date.
Coffee, canned ground
Unopened: 2 years
Opened: 1 month refrigerated
Coffee, gourmet
Beans: 3 weeks in paper bag, longer in vacuum-seal bag (After this time, color or flavor may be affected, but product is still generally safe to consume.)
Ground: 1 week in sealed container
Coffee, instant
Unopened: Up to 2 years
Opened: Up to 1 month
Diet Soda (and soft drinks in plastic bottles)
Unopened: 3 months from "best by" date.
Opened: Doesn't spoil, but taste is affected.
Dried pasta
12 months
Frozen dinners
Unopened: 12 to 18 months
Frozen vegetables
Unopened: 18 to 24 months
Opened: 1 month
Honey
Indefinite shelf life
Juice, bottled (apple or cranberry)
Unopened: 8 months from production date
Opened: 7 to 10 days
Ketchup
Unopened: 1 year (After this time, color or flavor may be affected, but product is still generally safe to consume.)
Opened or used: 4 to 6 months (After this time, color or flavor may be affected, but product is still generally safe to consume.)
Maple syrup, real or imitation
1 year
Maraschino cherries
Unopened: 3 to 4 years
Opened: 2 weeks at room temperature; 6 months refrigerated
Marshmallows
Unopened: 40 weeks
Opened: 3 months
Mayonnaise
Unopened: Indefinitely
Opened: 2 to 3 months from "purchase by" date (After this time, color or flavor may be affected, but product is still generally safe to consume.)
Mustard
2 years (After this time, color or flavor may be affected, but product is still generally safe to consume.)
Olives, jarred (green with pimento)
Unopened: 3 years
Opened: 3 months
Olive oil
2 years from manufacture date (After this time, color or flavor may be affected, but product is still generally safe to consume.)
Peanuts
Unopened: 1 to 2 years unless frozen or refrigerated
Opened: 1 to 2 weeks in airtight container
Peanut butter, natural
9 months
Peanut butter, processed (Jif)
Unopened: 2 years
Opened: 6 months; refrigerate after 3 months
Pickles
Unopened: 18 months
Opened: No conclusive data. Discard if slippery or excessively soft.
Protein bars (Power Bars)
Unopened: 10 to 12 months. Check "best by" date on the package.
Rice, white
2 years from date on box or date of purchase
Salad dressing, bottled
Unopened: 12 months after "best by" date
Opened: 9 months refrigerated
Soda, regular
Unopened: In cans or glass bottles, 9 months from "best by" date
Opened: Doesn't spoil, but taste is affected
Steak sauce
33 months (After this time, color or flavor may be affected, but product is still generally safe to consume.)
Tabasco
5 years, stored in a cool, dry place
Tea bags (Lipton)
Use within 2 years of opening the package
Tuna, canned
Unopened: 1 year from purchase date
Opened: 3 to 4 days, not stored in can
Soy sauce, bottled
Unopened: 2 years
Opened: 3 months (After this time, color or flavor may be affected, but product is still generally safe to consume.)
Vinegar
42 months
Wine (red, white)
Unopened: 3 years from vintage date; 20 to 100 years for fine wines
Opened: 1 week refrigerated and corked
Worcestershire sauce
Unopened: 5 to 10 years (After this time, color or flavor may be affected, but product is still generally safe to consume.)
Opened: 2 years
Until it's expiration date on the package. With fresh foods such as fruits and vegetables it can vary depending on the environment it is stored in.
5 years
You can freeze many foods. Some foods can be salted. Canning or putting it into jars can keep many foods fresh. You can also pickle or brine some foods. Some foods keep well if you just seal them into plastic.
all and any foods should not be kept longer than 3 days before canning/jarring.
This food should not be left out. Cooked foods should be cooled quickly for cold storage. It can only take a hour for cooked foods to be contaminated.
freezing
the body can be kept for a least 6 days before it starts to rott and the body turns purple and blue.
I have heard from the Red Cross that it can only be kept for 45 days, but is usually used long before then.
It depends on where you are. Heres a list of how long different records should be kept. I think this is in the UK
30 minutes
Food left out of the refrigerator is okay to eat for about 2 hours. If the temperature is under 80 degrees. The longer a food stays in the danger zone the more risk you take eating that food. Foods should either be kept hot or kept cold before eating to be really safe.
MRI films are kept as long as necessary, especially if you see the same doctor. You can have records transferred and then your new doctor will have them. They are consistently kept on record for years before they are not needed.
Most food used at fast food restaurants is frozen, so it is not actually fresh. How long it is frozen before it is used is not known. After food are cooked, there is a hold time for how long it can be kept under the warming lights. Foods like lettuce that cannot be frozen usually contain preservatives to make it look fresher longer, but it is not known for how long.
Lets explain this again. Meats that are left in the danger zone can have bacteria grow with in an hour. Meats should be kept cold before cooking and cooled fast after to insure the meat stays safe. Do not leave any foods out.