Onions and Tears?

Question

What do onions have in them, that when cut, make your eyes sting and tear?

Answer 1

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 2

Technically speaking, the onion contains "syn-propanethial-S-oxide" which irritates your eyes.

There are dozens of tricks on how to cut down on the tears. Just remember this: When you cut the onion, you break open the cells that hold the chemicals. The sharper the knife you have, the least amount of chemical you'll release into the air. So don't use a dull knife!

Answer 3

When certain onions are cut or chopped, they release "mystery" vapors that cause eyes to water. These are called "reflex tears".
To avoid this phenonema, never cut or chop onions.

Answer 4

light a candle a few minutes before you cut an onion and keep it close to you while cutting and it should burn out a lot of the smell and the fumes in the air from the onion, works well for me!!!

Answer 5

the best way i learned to cut an onion up and keep away the tears was run it under cool running water. it helps a big bunch. good luck

Answer 6

you desire Onion Goggles: Say see you later to ripping, stinging, annoyed eyes whilst reducing, mincing, dicing and reducing onions and their relativesleeks, scallions and chives. wearing the known and gentle Onion Goggles will preserve the eyes from stressful onion vapors. The gentle foam seal keeps out the nasty onion vapors. whilst onions are decrease, an enzyme called sulfoxide lyase and sulfuric compounds are released from the broken cells. whilst uncovered to air, they react with one yet another to sort a vapor. As this vapor evaporates, it irritates our eyes and motives us to cry. Kitchen folklore remedies which includes burning candles or fits, reducing onions under water and freezing the onions until now reducing are no longer valuable.

Answer 7

I don't know, but to avoid the sting, while cutting onions wear large sunglasses! It works!

Answer 8

its the onion juice. If you do not want this to happen cut them on the end where there is no roots and cut under running cold water and do not put your hands to your face.

Answer 9

Onions produce the chemical irritant known as syn-propanethial-S-oxide. It stimulates the eyes' lachrymal glands so they release tears.

Answer 10

some onion are real strong so soak them [peeled] in salt and water for a hour then cut up that will help