Why do onions make my eyes water when I cut them?

Answer 1

Put the onion in the freezer for fifteen min., then cut it NO TEARS!!!!

Answer 2

When you slice through an onion, you break open a number of onion cells. Some of these cells have enzymes inside of them, and when they are sliced open, the enzymes escape. The enzymes then decompose some of the other substances that have escaped from sliced cells. Some of these substances, amino acid sulfoxides, form sulfenic acids, which then quickly rearrange themselves into a volatile gas.

The gas reaches your eyes and reacts with the water that keeps them moist. This changes the chemical's form again, producing, among other things, a mild sulfuric acid, which irritates the eyes. The nerve endings in your eyes are very sensitive and so they pick up on this irritation (this is why our eyes sting when we slice onions). The brain reacts by telling your tear ducts to produce more water, to dilute the irritating acid so the eyes are protected. Your other reaction is probably to rub your eyes, but this will actually make the irritation a lot worse, of course, if you have onion juices all over your hands.

Oddly enough, this volatile compound is also responsible for a lot of the great taste in onions, as well as the pleasant aroma when you cook the vegetable. You'll also get sulfenic acids by cutting up garlic, chives and leeks, among other vegetables, but they don't form the same irritating gas, just a strong smell.

There are all kinds of remedies for dealing with this irritating phenomenon, some more effective than others. As a general rule, move your head as far away from the onion as you can, so the gas will mostly disperse before it reaches your eyes. If you really can't stand the tears, the simplest solution might be to wear goggles. This measure is very effective, but it may seem a bit extreme to those around you, and if your kitchen is steamy, you might not be able to see what you're doing (never a good idea when you're using a knife).

Peeling the onion and then chilling it in the refrigerator before you slice it will minimize the release of gas somewhat, because the change in temperature alters the compounds in the onion. Cooking an onion before you slice it will work also, for the same reason. Another easy solution is to cut the onion under water or run the tap over it as you slice.

Some people say if you hold a lemon, piece of bread or a sugar cube in your mouth, the food will absorb the gas before it reaches your eyes. Breathing with your mouth, instead of your nose, might also help because as you inhale, you suck the gas in and as you exhale, you blow it away. This keeps a lot of the gas from ever reaching your eyes

Answer 3

Onions may cause your eyes to tear for the following reason:

When you cut into an onion, you slice through cells which contain
sulfur compounds. Sulfur is quite a noxious (bad smelling)
element. The compounds released are highly volatile, meaning they
quickly enter the air in their vicinity. Your eyes produce tears
because your body wants to wash or dilute the chemicals before they
effect your eyes. The tears are a natural way the body can wash
the offensive chemicals away.
Since there are a variety of onions, we would expect there to be
a variety of amounts and types of sulfur compounds produced by them.
Think of it as different types of apples: some are red, some yellow,
some green, and they all taste a bit different due to different
chemical compositions. Onions are different in that way too.
Some are REALLY bad smelling, some only mildly bad smelling.

One further bit of information. The chemicals which I described above
are both volatile AND water soluble. This means if you cut the onion
while holding it under a spray of water, the chemicals will wash down
the drain and will not enter the air in as great an amount to cause
your eyes irritation.

Answer 4

I think it gives off a gas that makes your eyes tear up but I was told if you light a candle and
place it near when you cut the onion it will help
keep your eyes from doing this.

Answer 5

Teh Strenth Of The Scent

Answer 6

because when you slice into an onion you break tiny little cells wich release a gas, and when that gas mixes with the water in your eyes it creates a mild from of sulfuric acid....i know it sounds crazy but i am 100% positive of my answer

Answer 7

i dunno...but i know how not to make your eyes water...don't stare at the onion when u r cutting it...n keep your eyes as far as the onion as u can(:

Answer 8

IT IS BECAUSE THE ACIDITY IN THE ONIION HITS YOUR EYES AND MAKE THEM BURN

TRY USING A REALLY SHARP KNIFE OR CUT THEM UNDER WATER, IT WORKS EXTREMELY WELL

GOOD LUCK

Answer 9

ONIONS are LIKE MAN they always made u cry when Women CUT it

Answer 10

the scent is so powerful is makes ur eyes water