If you eat bad onions the worse that would likely happen is you get a bad stomach ache or slight food poisoning and may have diarrhea, abdominal pain, stomach cramps, etc.
Eating bad onions is unlikely to cause serious health issues but still it's not a good idea to eat bad onions.
However contrary to popular belief onions do not become toxic once cut open and left out overnight or for a few days.
I always cut up an onion and use half of the onion in hamburgers, with sausage etc and then leave the rest of the onion out for a few days while I use it.
I've never gotten sick from the onions even after cutting them and leaving them out.
Getting food poisoning from bad onions is possible but also very rare.
If the onions are bad and smell bad then throw them away and don't risk your health.
You can get food poisoning from onions if the onions are bad or have Salmonella.
There have been cases of where some people have gotten Salmonella Poisoning from bad onions although it's rare.
When onions are bad they will have developed brown, black or soft spots or the onion smells bad.
And if the onion changes colors or begins getting soft or squishy and smells bad then the onion is bad.
But if you cut the soft part of the onion off soon enough then you can use the rest of the onion safely.
Onions can be frozen but you should chop the onions up or mince the onions first and then put the onions in a freezer bag, Ziploc bag or plastic container.
Whole onions can be frozen but they may become soggy so it's best to chop the onions up first or mince the onions and then freeze them.
Eating raw onions have many health benefits and onions are healthiest when eaten raw.
Onions are healthy for you both raw and cooked although the raw onions are the healthiest for you.
Eating raw onions can boost your immune system, prevent cancer, improves your heart health and may protect against heart disease, heart attacks, strokes etc.
Raw onions are very healthy for you and eating raw onions have a lot of health benefits.
Onions when raw are packed full of nutrients, vitamins, antioxidants and much more which means that they can provide you with energy, improve your heart health, improve kidney health, improve liver health and improve your overall health.
Onions contain antioxidants, vitamins, minerals and a host of other nutrients.
The health benefits of onions include, improved energy, improved liver function, improved kidney function, prevention of heart disease, prevention of blood clots, improves digestive health, improves bone density, controls blood sugar, controls blood pressure.
Onions can also help fight cancer, boost your immune system, fight off infections, detoxes your body and onions also have anti inflammatory properties.
Eating onions too much could cause acid build up so be aware of that but onions when eaten in moderation are very healthy for you.