Beauty Tips For Body Care
I have seen lots of people shun a sunscreen because its only filter was titanium dioxide due to the speculation that it doesn't block the full spectrum of UVA rays; I, myself, judged sunscreens based in that in the past as well. I came across this scientific article and it was super helpful in clearing that up.I have posted part of the peer reviewed chapter on titanium dioxide and basically nano titanium dioxide is an effective broad spectrum agent. I have bolded the most relevant part.https://www.intechopen.com/books/application-of-titanium-dioxide/titanium-dioxide-in-sunscreenTitanium Dioxide in SunscreenBy Megha Trivedi and Jenny MuraseSubmitted: November 29th 2016Reviewed: March 29th 2017Published: July 26th 2017DOI: 10.5772/intechopen.68886"The efficacy of sunscreens is determined by the ability to protect against both UVB radiation and UVA radiation. As discussed in previous paragraphs, titanium dioxide sunscreens are effective broad-spectrum agents, meaning that they are capable of protection against both types of radiation. A sunscreen’s efficacy in protecting against UVB radiation is assessed based on two values: the sun protection factor (otherwise known as SPF) and substantivity. The SPF is calculated as a ratio of the amount of ultraviolet radiation needed to cause sunburn when the skin is protected with a certain sunscreen to the amount of ultraviolet radiation needed to cause sunburn when the skin is left unprotected. Therefore, if a product is SPF 30, then 30 times the UV radiation is needed to cause sunburn if the patient is wearing the sunscreen with that SPF value [10]. Generally, in order to be considered broad spectrum, a sunscreen must be at least SPF 30 or greater. Substantivity is another measure that sunscreens are subjected to when being evaluated for use in the United States. This measurement evaluates the ability of a sunscreen to withstand exposure to factors which can cause the physical removal of the agent off the skin (and still remain effective afterward). These factors include sweat and water, among others. By measuring the substantivity of a product, manufacturers can have insight into the product’s actual usability in the real-world setting. Interestingly, until 1933, many products were being labeled as “waterproof” based on superior product stability when tested with water immersion. However, the FDA released a statement disapproving the terminology as misleading since all products lose effectiveness after a certain amount of exposure. Now, the term “water-resistant” is more commonly seen on products [2].Efficacy of UVA radiation protection is often measured by immediate pigment darkening (IPD), persistent pigment darkening (PPD), and protection factor (PFA). Both IPD and PPD measure photo-oxidation of melanin in the skin which contributes to skin pigmentary changes. However, PPD is seen as the better measure in most cases, as the measurement takes place 2–24 h following exposure to radiation unlike IPD which reaches peak levels within 1 min of exposure. PPD also measures the photostability of the sunscreen being tested. Protection factor measures redness and tanning 24 h after UV radiation exposure and can also be used to test UVA protection efficacy [2].Both titanium dioxide and zinc oxide sunscreen formulations have several advantages as inorganic blockers. These agents are not only effective against UV radiation but also protect against infrared radiation and visible light. As mentioned before, titanium dioxide is chemically inert—this is useful since in most cases, titanium dioxide is combined with other organic sunscreens and does not react with other ingredients in the compound. In the past, both titanium dioxide and zinc oxide sunscreens were less preferred due to their chalky, white appearance on application. However, micronization of particles and more recently “nanoparticle” formulations have made TiO2 sunscreens more popular in recent years [11]. Early studies comparing micronized versions of TiO2 versus micronized versions of zinc oxide sunscreens concluded that micronized zinc oxide sunscreens were superior as they conferred better protection against longer wave UVA and had greater cosmetic outcomes [12]. However, nanoparticle formulations of TiO2 have virtually replaced all other forms in the sunscreen market and these sunscreens have demonstrated great effectiveness. Nanoparticle TiO2 sunscreens not only have superior cosmetic outcomes as these product are virtually invisible upon application, but they also possibly confer greater UV protection. One study published by Tyner and colleagues in 2011 demonstrated that nanoparticle TiO2 may have greater UV radiation attenuation. The authors also commented that overall formulation of the sunscreen is important when attaining high levels of efficacy. The best TiO2 sunscreens occur when particles are coated, stabilized, and distributed evenly on the surface of the skin. Coated nanoparticles are very effective at non-agglomeration and therefore distribute effectively on the skin surface [13]. It is also important to note that the vehicle of the sunscreen can also affect effectiveness. The best vehicles avoid significant interaction between active and inactive ingredients. Vehicle also affects the substantivity measure of the sunscreen since the vehicle is often the main determinant of how well the sunscreen resists water, sweat, and other environmental factors. The vehicle types currently available include lotions and creams, gels, sticks, and sprays. Gels are often the most sensitive to water and sweat removal [3]."
Girls Blog 2015
Submitted by mshl_meow
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