Precaution about left over onions

I have taken the idea of this post through an email which I received recently. As we try to save our time and money by reusing or recycling our food, we might use the left over onions for making food.
Are left over onions safe for reuse? The simple answer is no, left over onions are very harmful. 

LEFT OVER ONIONS ARE POISONOUS

When someone gets sick, we blame oily foods while nobody cares about the bowl of potato salad sitting on the table. Mostly when we suffer from food poisoning, we assume that it might be due to the use of mayonnaise. Usually commercially made mayonnaise is completely safe. It doesn't even have to be refrigerated. No harm in refrigerating it, but it's not really necessary."
The pH in mayonnaise is set at a point that bacteria could not survive in that environment.



When food poisoning is reported, the first thing the officials look for is when the 'victim' last ate ONIONS and where those onions came from (in the potato salad?). It's probably the Onions, and if not the onions, it's the POTATOES.

The fact is that onions are a huge magnet for bacteria, especially uncooked onions. You should never plan to keep a portion of a sliced onion.. It is not even safe if you put it in a zip-lock bag and put it in your refrigerator. It's already contaminated enough just by being cut open and out for a bit, that it can be a danger to you (and doubly watch out for those onions you put in your hot dogs at the baseball park!)

If you take the leftover onion and cook it like crazy you you'll probably be okay, but if you slice that leftover onion and put on your sandwich, you're asking for trouble. Both the onions and the moist potato in a potato salad, will attract and grow bacteria faster than any commercial mayonnaise will even begin to break down. Also, dogs should never eat onions. Their stomachs cannot metabolize onions.

Please remember it is dangerous to cut an onion and try to use it to cook the next day, it becomes highly poisonous for even a single night and creates toxic bacteria which may cause adverse stomach infections because of excess bile secretions and even food poisoning.