In children, SLS has been linked to eye irritation and poor eye development. Even at very low levels, the product may be absorbed through the skin and cause issues with eye health. It would seem that children’s products should be scrutinized more closely, but often they are not. A number of studies have indicated that SLS will remain in a person’s system (Brain, Heart & Liver) for up to 4-5 days which means if you are using a non SLS free product at the same volume and same rate of application then Sodium Lauryl Sulfate will remain a constant in your body.
Biosurfactants are surface-active substances synthesised by living cells. Interest in microbial surfactants is due to their diversity, environmentally friendly nature, possibility of large-scale production, selectivity, performance under extreme conditions, and potential applications in environmental protection.   A few of the popular examples of microbial biosurfactants includes Emulsan produced by Acinetobacter calcoaceticus ,  Sophorolipids produced by several yeasts belonging to candida and the starmerella clade,   and Rhamnolipid produced by Pseudomonas aeruginosa  etc.
Immature lungs of a preterm infant often fail to produce sufficient surfactant, which leads to respiratory problems. Commonly used is the lecithin-sphingomyelin ratio ("L/S ratio"), where a L/S ratio of less than 2:1 means that the fetal lungs may be surfactant deficient, which can result in infant respiratory distress syndrome (IRDS) and ultimately neonatal death. Another recent ratio used is the surfactant/albumin (S/A) ratio, where a S/A ratio of less than 35 indicates immature lungs, between 35-55 is indeterminate, and more than 55 indicates mature surfactant production (which correlates with a L/S ratio of or greater).