Sunscreens make their action by absorption of UVA and UVB radiation. Most used products are Benzophenones 1, 2 (BP-1, BP-2), p-aminobenzoic acid derivatives (PABA), 3-4 Methylbenzylidene camphor (3-4 MBC), Octyl-methoxy cinnamate (OMC), Salicylates, Avobenzone and Diethyl-phthalate homosalate (HMS). Many synonyms are used by the cosmetic industry to nominate these products. Chemical sunscreens are absorbed and deposited in the skin and can reach important amount into the blood stream. Some compounds have been found among 85% of swiss women tested. Since some of them have shown to have the potential of disruption of the endocrine system that may affect the genital-sexual tract and the hypothalamus-hypophysis-thyroid axis in the infant should be avoided while breastfeeding. Physical sunscreens act as a barrier that reflect all types of sun radiation. Most commonly used are: Zinc oxide (ZnO), Titanium oxide (TiO2) and Calcium or Magnesium carbonates. Physical sunscreens are not absorbed by skin mostly on not-nanoparticle formulation. Because of this, these are considered to be of choice while breastfeeding. Both types of sunscreens, whether chemical or physical, are environmental contaminants of the sea with deleterious effect on Phytoplankton and coral reef. Sunscreens should never be used as substitute of other preventive measures known to be more effective like avoidance of long-lasting sun exposure, higher exposure hours, promotion of wearing of clothes, hats, sun glasses and shadowed shelters. Do not apply it on the breast or cleanse it thoroughly to keep the baby from swallowing. In addition, there is evidence that they may block or inhibit formation of vitamin D3 by skin.