Allicin in onion can stimulate lacrimal gland to secrete tears, refresh the mind, promote sleep, promote metabolism, enhance physical strength, eliminate fatigue, improve attention and promote brain activation.
Newly renovated houses will inevitably have a strong smell of formaldehyde. Putting some onions can improve it, because the adsorption molecules of onions are larger than formaldehyde, which can mask the smell of formaldehyde. After putting onions, the smell of formaldehyde can be quickly removed.