This ingredient group broadly has 3 areas of concern; contamination, irritation and allergies, and being harsh on skin, scalp, and hair.
1. Contamination and difference to ammonium lauryl sulfate
What potentially could make ammonium laureth sulfate harmful, is that it could be contaminated with the toxic and carcinogenic chemicals ethylene oxide and 1,4-dioxane.
The reason is the chemical composition. In order to make the chemical ammonium lauryl sulfate gentler, it goes through an ethoxylation process.
Which, simplified, means that ethylene oxide is added to ammonium lauryl sulfate and while this happens, another chemical reaction occurs. And in that reaction, 1,4-dioxane is formed.
The ethoxylation process is visible in another name for this ingredient is ammonium lauryl ether sulfate.
In other words, it is not a surprise nor a mistake that the product might be contaminated. And most importantly, there is no guarantee whatsoever that a product containing this ingredient is free of toxic impurities just because it is “eco”, “natural” or “organic”. All ethoxylated chemicals have the same risks.
So to clarify, to make ammonium lauryl sulfate less harsh, ethylene oxide is added, and that then becomes ammonium laureth sulfate.
2. Irritation and allergies
The European Chemicals Agency (ECHA) identifies that
“this substance causes serious eye damage and causes skin irritation“.
3. Is ammonium laureth sulfate (and ammonium lauryl sulfate) bad for hair and skin?
The easy answer is that for most, Yes. This is due to the sulfates that are known to be aggressive cleansers and drying. Both ammonium laureth sulfate and ammonium lauryl sulfate are bad for hair. Especially for color treated, dry, long or afro-textured hair.
What the chemical do is to help mix water with oil, thus removing potential dirt. However, as a result, also our body’s and hair’s natural oils are stripped.