The ingredients below all appear in at least one of the toothpastes reviewed, and have all created some argument amongst experts. This doesn’t mean that they are definitely unsafe, but it is wise to treat them with caution. The ingredients are not listed in any particular order regarding safety.
Sodium lauryl sulfate
This is a foaming agent, commonly used in toiletries. It makes the toothpaste spread more easily through the mouth to remove food.
The main concern with sodium lauryl sulfate is that in some people it causes irritation, particularly round the eyes. Sometimes sodium lauryl sulfate is made from petroleum, but it can also come from plant sources: coconut oil or palm kernel oil. The version used in natural toothpastes is made from plant sources. (Palm kernel oil has its own issues, since some rainforest destruction is due to felling trees to plant palms.)
With regard to the safety of plant based sodium lauryl sulfate, a good place to look is at the American website EWG (Environmental Working Group.) This group evaluates the safety of cosmetics and toiletries and is much more rigorous in its testing than the FDA. They class sodium lauryl sulfate as low concern, with moderate concern regarding toxicity in non-reproductive organs. (Overall it receives a rating of 1 – 2, which is low concern.)
My view is that for very young children it would probably be safest to avoid sodium lauryl sulfate, and for older children who can spit toothpaste out, it is probably okay – so long as you can be sure the origin is plant rather than petroleum. But if your child has allergies it may be best avoided.
Sodium Lauroyl Sarcosinate
This ingredient sounds similar to sodium lauryl sulfate, and is used for the same purpose. It is made from caffeine or creatine. Some manufacturers claim in it is a safer alternative, but EWG rate it at 3, which is of moderate concern. It is approved by the FDA under the following conditions: for use in rinse off products such as shampoo or in concentrations of less than 5% in products that are left on. This also leads me to think that of the two, sodium lauryl sulfate is the safer option.
This is a preservative that some companies producing natural toiletries use instead of parabens, but other sources consider it no safer. The EU has classed it as safe to 0.5%, and it is commonly used in considerably smaller quantities. Nevertheless, under certain conditions it can release formaldehyde and therefore could be potentially carcinogenic. EWG includes it in a list of preservatives of particular concern, but somewhat confusingly, when listing it individually the site classes it as “medium concern.”
This is a sugar alcohol, and is often used instead of sugar. Some people say it is safe, because it is not fully absorbed by the body. However, it has a long list of possible side effects, from diarrhea and bloating to dizziness, and breathing problems. The FDA does not recommend this sweetener for children under the age of three. Yet, it appears in 2 of these toothpastes.
Xylitol is not related to sorbitol, and is usually considered to be more natural. Dentists like it because it is not harmful to teeth. But it can also cause stomach pains and diarrhea in relatively small amounts. It’s unlikely your child would consume those amounts by swallowing toothpaste during brushing, but like sorbitol, it’s probably best avoided.