General Health Information

However, it is not just the bleaching agent itself that you need to
concern yourself with when trying to minimize chances of soft tissue
irritation. Humectants are ingredients found in teeth bleaching kits
and they are there to prevent the product from drying out. Propylene
glycol is one such ingredient used for this purpose and it is also a
very common thing to find in antifreeze. If this gets on your gums,
cheeks, or tongue, then irritation is likely.