Former president of health foods grocery chain Trader Joe's said this week that he planned on opening a store that sold expired food with huge discounts, several people responded with the obvious question: is that even safe?

Food products that have bypassed their expiration dates are commonly equated to food poisoning, something that contributes to billions of dollars worth of food straight into the trash. How much exactly? Think $160 billion dollars worth.

Food and Agriculture expert Dana Gunders explains, putting food misconceptions to rest: "Food-borne illness comes from the contamination of food by salmonella, listeria, and other pathogens. They get on the food during production and processing. That's what leads to people being sick, not the age of the food."

Looking at the expiration date on the label is the only way we can tell if food is still OK to eat, but in fact, the only food products that the Federal Food and Drug Administration strictly regulates is baby formula. The rest is overseen by the food companies. "Some [food companies] may use actual lab tests, but that's pretty rare," says Gunders, "They might do consumer testing, or they might guess according to how competitors are labeling."

So by what standards can you measure if a food product in your fridge is way past expiration date or not? Gunders and other experts say you can do that on your own-with your eyes, nose, and your common sense.

Food safety expert Ted Labuza shares his tips on keeping food-no matter what the expiry date says.

He keeps his refrigerator lower than 40 degrees-"the recommended temperature-to 32 and 34 degrees, thus giving food precuts such as meat and milk a 50% longer shelf life. Labuza adds that stores don't really scientifically test their meats to tell for how long they're going to last, but instead copy the dates used by their competitors.

Labuza says that the key to making food last is storage temperature and keeping the products away from oxygen and moisture.  Canned goods normally last three years, but can be extended to seven years if places in a cool place-away from the stove and other warm places. The same could be said of jarred and bottled goods, but he adds that those with dents should always be thrown away.

He then says that there is no problem to eating any frozen food, as freezing kills all the spoil-causing microbes and bacteria. Frozen food will tend to look bad due to freezer burn, which occurs when a bit of air is present in the packaging. Bread and other wheat products are extended mightily well when frozen.

Stale dry goods such as crackers and chips should be oven-toasted to give them a new crisp, but Labuza says that if they smell rancid, it means the the oil has spoiled, and should immediately be thrown away.

Eggs, despite what their label says, can still be edible as long as they sink in a bowlful of water; if their float, it means they are spoiled.

Vegetables that look wilted can be rejuvenated in a quick bath of ice water.

But Labuza warns against processed foods like prepared cold cuts and hotdogs, which most likely acquire deadly pathogens during processing. Cooking will kill surface bacteria, but he recommends that the very young and the elderly-or anyone with compromised immune systems stay away from them completely.