A newborn’s skin is thinner, less developed as a barrier, and covers a much larger surface area relative to body weight than an adult’s — all of which means fragrance ingredients are absorbed more readily and affect a newborn proportionally more than the same amount would affect a grown adult.

The Skin Barrier Is Still Forming

The outer protective layer of skin, the stratum corneum, is not fully mature at birth and continues developing over the first weeks and months. That makes it easier for anything applied to the skin — including alcohol and fragrance compounds — to penetrate further than it would in older children or adults, increasing the chance of irritation or a reaction.

Surface Area Makes a Real Difference

Because babies are small, their skin surface area relative to their overall body weight is much higher than an adult’s, so a small amount of product applied to a baby covers proportionally far more of their system than the same amount would on an adult. This is exactly why paediatric guidance generally recommends avoiding fragranced products directly on newborn skin. Our perfume allergies and sensitive skin guide and dedicated family and children’s safety guide both go into this properly, and both sit within the complete guide to perfume.