You are exposed to this harsh chemical every day, and you might even eat it from your toothpaste because the absorption of SLS is more from oral mucosa and so, is the chance of accidentally eating it

Here is the list of side effects that SLS has on oral mucosa:

• SLS increases permeability of mucosa to both oil and water soluble substances, thus, might result in absorption of those harmful substances which otherwise would not be absorbed from mucosa. So, SLS itself will increase its own absorption.
• Sodium lauryl sulfate interacts with the deposition of fluoride on dental enamel, due to which the caries inhibition by fluoride might be affected.
• SLS at low concentrations 0.15% has shown damage and death of cells in oral mucosa.
• In a study, subjects were exposed to SLS and SLS-free toothpaste for 2 minutes for 4 consecutive days. Desquamation or damage to oral epithelium was experienced following exposure to SLS-containing toothpaste and not with SLS-free paste.
• In another similar study, SLS toothpaste showed irritant effect with just single 15 minutes exposure.
• SLS can increase chances of getting aphthous ulcers; so if you get frequent small ulcers in mouth, check if your toothpaste has SLS.
• Few may argue that SLS reduces bacterial count, however, one study proves that chlorhexidine  has a better anti-bacterial effect than SLS and triclosan (another controversial ingredient).

What you can do?

Always check the ingredient list of your toothpaste for presence of SLS, which can be listed by following names:

• Sodium Lauryl Sulphate
• Sodium dodecyl sulfate
• Sulfuric acid, monododecyl ester, sodium salt
• Sodium salt sulfuric acid