You might ask why these ingredients aren’t listed in the ingredients list, but often they are, sort of. You might be surprised to know that contaminants such as Formaldehyde and 1,4-dioxane do not need to be disclosed because legally they are not considered ingredients. The code words quaternium-15, DMDM hydantoin, imidazolidinyl urea and diazolidinyl urea indicate Formaldehyde, acting as a preservative, as a by-product. Products that contain PEG-100 stearate, sodium laureth sulfate, polyethylene and ceteareth-20 indicate contamination with 1,4-dioxane. Why you need to carry a dictionary with you to know what’s in your baby products is a whole other issue.... But read your labels!
While you’re at it, look at some of the ingredients in your own product lineup. You’d be surprised to see how toxic your makeup can be. You might be thinking that the levels might be so tiny, trace as they like to call it... but if you think about your own and your children’s daily exposure, a little can add up over time. The toxins don’t exactly go anywhere; they just build up. If your child is having an “allergic” reaction to her shampoos or lotions, that allergy might very well be attributed to formaldehyde or 1,4-dioxane.... Make the switch to simpler ingredients and fragrance-free products.... California Baby's Super Sensitive Shampoo and Body Wash  with a toxic rating of 0-1 and is available at Target and widely available.
EWG's Safety Guide to Children’s Personal Care Products .