The American Academy of Dermatology (AAD) has declared the use of sunscreens containing titanium dioxide and zinc oxide nanoparticles safe for protection from the sun's harmful ultraviolet rays.
By shielding the skin from ultraviolet rays, these types of sunscreens prove to be very useful in the prevention of skin cancer. Ronald L. Moy, the President of the Academy, reiterated the importance of using sunscreen in the prevention of skin cancer, in particular melanoma and premature aging of the skin by effectively blocking UVA and UVB rays.
Sunscreens are composed of active drug ingredients that are capable of scattering, absorbing or reflecting the UV light. Some media reports were skeptical about the use of sunscreens that contain retinyl palmitate and oxybenzone and also the application of nanotechnology in sunscreens. Dr. Moy confirmed that none of these substances are health hazards. In fact oxybenzone has been approved for use in sunscreens by the FDA since 1978, and retinyl palmitate is a form of vitamin A and is not an active drug ingredient of sunscreens. He added that the use of nano-sized titanium dioxide and zinc oxide particles to sunscreens increased their effectiveness at blocking UV rays.
Dr. Moy stated that although extensive use of nanotechnology in the field of medicine is presently under examination, nanoparticles present in sunscreens are more effective in protection from UV rays as their small size allows them to cover a larger surface area of the skin compared to larger particles. he went on further to say that, the outermost stratum corneum layer of the skin prevents nanoparticles from entering the sub layers, thus rendering the use of nanoparticles in sunscreen safe.
Dr Moy was quoted as saying, "While widespread use of nanotechnology in medicine is currently under evaluation, one of the main benefits of nanoparticles in sunscreens is that the small molecules can provide more protection and more even coverage on the skin’s surface than larger particles". He went on further to reinforce his point that nanoparticles were safe to use in sunscreens by saying, "Considerable research on the use of nanoparticles on healthy, undamaged skin has shown that the stratum corneum – the outermost layer of the skin – is an effective barrier to preventing the entry of nanoparticles into the deeper layers of the skin. Titanium dioxide and zinc oxide have a long history of safe use in sunscreens and offer good options for broad-spectrum UV protection."
Source: http://www.aad.org/