Eating food that's been left at room temperature is a bad idea.
Sure, we’ve all been mid-meal, wandered off to do something else before coming back to finish off our cold, slightly sorry looking food.
After all, what difference can there really be between pizza fresh out of the box and pizza that has spent a few on the sitting room floor?
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Well, as it happens, the answer is quite a lot.
So how long can you leave food at room temperature without risking falling ill?
Here's everything you need to know...
How long can you leave food at room temperature?
In America, the Food and Drug Administration (FDA) federal agency has clear rules.
The FDA states that you should "discard any perishables left out at room temperature for more than 2 hours, unless you’re keeping it hot or cold."
This news is obviously a blow to those of us who like nothing more than revisiting a Friday night takeaway.
If you've left your food at room temperature for more than two hours, there are risks.
According to the FDA, not following this rule could result in damaging side effects of unwelcome bacteria.
How can you safely store leftover food?
Food Insider, it's all about timing and temperature.
"If the food is being kept in an area that is 90 degrees Fahrenheit (32.2 degrees Celsius) or above, leftovers should be refrigerated," it states.
Food should be refrigerated at "40 degrees Fahrenheit (4.4 degrees Celsius) or below within one hour".
Check out our recipe for delicious Leftover Roast Chicken Biryani:
What happens if you leave food at room temperature?
Scientists agree that most species of bacteria grow most rapidly between 40 degrees and 140 degrees Fahrenheit.
This range is ominously referred to by the USDA as “the danger zone”.
It is between these two temperatures where scientists from the University of Lincoln Nebraska have reportedly seen a single bacterium “grow to over 2,097,152 bacteria in seven hours”.
Obviously, this a potential catastrophe for anyone with a sensitive tummy.
Will I get ill?
Sadly, there is a risk you'll fall ill.
The United States Department of Agriculture explained that this is because "bacteria exist everywhere in nature.
Unfortunately, this means that "leaving food out too long at room temperature can cause bacteria to grow to dangerous levels that can cause illness."
Illness-inducing bacteria include Staphylococcus aureus, Salmonella Enteritidis, Escherichia coli O157:H7, and Campylobacter.
This is of course bad news for anyone who enjoys stale, two-day-old egg fried rice.
What if you reheat the food?
Unfortunately, reheating your food isn't necessarily a solution.
The Washington State Department of Health has warned of the risks.
It said: "Both staphylococcus and bacillus cereus produce heat-resistant toxins that cannot be destroyed with high temperatures."
With that in mind, is it really worth the risk?
Is it safe to eat?
Obviously not all food left overnight will result in death or illness.
We’ve all eaten something that may have seen better days, with many of us avoiding any side effects altogether.
But, as these studies prove, it may only be a matter of time before something serious happens.
You can try to outrun fate for as long as you like but eventually, it will catch up with you.