Question: Last night, I ordered in some pizza and then fell asleep for a few hours before I could put away the leftovers. The pizza was sitting on the counter for a total of about 6 hours before I put it in the fridge. It still smells fine — is it safe to eat?"
Answer: Sorry, but you're out of luck.
According to the United States Department of Agriculture, it’s dangerous to eat any cooked food (including takeout foods like pizza, fried chicken or Chinese food) that has been allowed to sit at room temperature for two hours or longer.
The reason is that temperatures between 40° F and 140° F provide the perfect breeding environment for so-called “pathogenic bacteria” — the kind of bacteria that causes foodborne illness. And here’s the tricky part: Pathogenic bacteria generally does not affect the taste, smell, or appearance of food. In other words, just because the pizza smells ok to you, that doesn’t mean it’s safe to eat.