They also noted that no particles were found in the viable sections of skin tissue [ 17 ]. Pflucker and colleagues published a study in which used electron and light microscopy to evaluate whether dermal penetration of micronized titanium dioxide particles occurred to any measurable degree. Their results suggested that particles could only be found in the top most layer of the stratum corneum and further penetration into deeper layers of stratum corneum, epidermis, or dermis was not noted [ 18 ].
Sadrieh and colleagues conducted a similar more recent study in using electron microscopy-energy dispersive x-ray analysis and again noted that there was no significant penetration of particles past the intact epidermis [ 19 ]. A general review of the toxicology of titanium dioxide nanoparticles by Shi and colleagues was published in They concluded that most dermal exposure studies with TiO 2 had not found significant penetration of particles into deeper layers of skin.
However, the review noted that long term studies of TiO 2 inhalation were associated with lung tumors in rats. Several reviewed studies also suggested that intravenous injection of TiO 2 nanoparticles could potentially result in pathological lesions to a variety of internal organs [ 20 ]. The current opinion and recommendation on nanoparticles is controversial with the data that has been presented in recent years.
Another potential health and safety concern with the general use of sunscreens is the potential of vitamin D deficiency. Appropriate vitamin D synthesis necessitates certain levels of UVB exposure and the American Academy of Dermatology has recently revised its position on sunscreen effects on adequate vitamin levels. They note several populations are at higher risk for vitamin D deficiency including the elderly, darker skinned those who live in areas of low sunlight exposure, the obese, and the photosensitive.
It is generally recommended that individuals obtain international units of vitamin D daily and some may have to supplement this through oral formulations [ 3 ]. Unlike other organic sunscreens, the inert nature of titanium dioxide sunscreens makes it one of the least likely compounds to cause irritation and sensitization of the skin. In fact, because of its chemical inertness and lack of photoreactivity, it is often the preferred sunscreen for individuals with sunscreen allergies and children [ 3 ].
However, in recent years an interesting interaction between gold allergic patients and titanium dioxide has been proposed and studied. In , Nedorost and Wagman hypothesized that patients with facial and eyelid dermatitis may be experiencing reactions due to an interaction between their gold jewelry earrings, bracelets, etc. Mechanistically, titanium dioxide was thought to adsorb gold particulate matter which then caused contact dermatitis in the locations of makeup application. Their results demonstrated a subgroup of individuals who used TiO 2 containing makeup on areas then affected by contact dermatitis, benefiting from gold jewelry avoidance, lending credence to the interaction theory [ 22 ].
In , Danesh and Murase published a clinical pearl in the Journal of the American Academy of Dermatology regarding a trial of gold avoidance in patients presenting with eyelid allergic contact dermatitis. They noted that the North American Contact Dermatitis Group implicated gold as the most common allergen to cause eyelid dermatitis most likely through a mechanism in which eyelid cosmetics containing titanium dioxide particles adsorbed gold particles from elsewhere on the body [ 23 ].
The American Academy of Dermatology has set forth guidelines for appropriate sunscreen use and sun protection. These include sunscreens with sun protection factors greater than Sunscreen should be applied 15—30 min prior to sun exposure and be reapplied as needed when environmental factors swimming and sweating cause sunscreen removal [ 3 ].
In conclusion, titanium dioxide sunscreens are effective agents against UV radiation. They also have an advantage as they protect against multiple wavelengths of energy including UV radiation, visible light, and infrared radiation.
Furthermore, unlike organic compounds, titanium dioxide, like its zinc counterpart, is a chemically inert substance, and therefore, there is less concern about reactivity in terms of toxicity profiles and allergic reactions. Although these agents were not heavily marketed in previous decades due to their thick, chalky appearance on the skin, the development of nanoparticle formulas improved their cosmetic profile.
Nanoparticle formulations are considered effective sun protection agents as well as cosmetically acceptable. Concerns about safety with induction of radical oxygen species on the skin as well as absorption have been discussed.
However, current evidence does not support claims of nanoparticle toxicity to humans. With this said, a greater number of studies with longitudinal data will be helpful in further informing this topic. Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution 3. Help us write another book on this subject and reach those readers.
Login to your personal dashboard for more detailed statistics on your publications. Edited by Magdalena Janus. We are IntechOpen, the world's leading publisher of Open Access books.
Built by scientists, for scientists. Our readership spans scientists, professors, researchers, librarians, and students, as well as business professionals. Downloaded: Abstract Titanium dioxide has been used in various industrial and cosmetic applications due to its unique elemental properties.
Keywords titanium dioxide in sunscreens titanium dioxide skin allergic contact dermatitis. Notes These wavelength ranges vary depending on the source of the text. More Print chapter. These ingredients are tasked with degrading or deactivating sunlight, creating a chemical reaction that transforms UV rays into heat, which is then released from the skin.
Physical sunscreen , on the other hand, is made of natural compounds that sit on the surface of the skin. These ingredients act similarly to aluminum foil or a mirror, keeping sunlight from penetrating deeply. Zinc oxide and titanium dioxide sunscreens fall into this category. Physical sunscreen lasts longer when in direct UV light , while chemical sunscreen stops working much more rapidly and must be applied more frequently.
Physical sunscreen is gentle on the skin and less likely to clog pores, making it better for sensitive skin , while chemical sunscreen is much harsher. More questions about sunscreen safety? Use our safety resource on chemical ingredients used in sunscreen. However, extensive studies on titanium dioxide industry workers do not suggest an association between occupational exposure to titanium dioxide and an increased risk for cancer in humans. Pigment-grade titanium dioxide is manufactured at a specific particle size distribution to optimize the scattering of visible light and enhance surface opacity.
Titanium dioxide is produced primarily in the pigmentary form over 98 percent of total production , which makes use of its excellent light-scattering properties for a range of applications that require opacity and brightness. Titanium dioxide nanomaterials are purposefully made in a much smaller particle size distribution than pigmentary particles and are transparent and more effective as UV absorbers or photocatalysts. The transparency and UV absorbance allow for effective use as a protective ingredient for sunscreens.
Titanium dioxide is often used to impart whiteness to food products, cosmetics and personal care items, like toothpaste. Food and Drug Administration FDA has assessed the safety of titanium dioxide as a color additive and has issued regulations approving the ingredient for these purposes.
Titanium Dioxide Manufacturers Association. American Chemistry Council. Personal Care Products Council. Tweets by AmChemistry. Home Titanium Dioxide Titanium Dioxide. What is Titanium Dioxide? If you're using one of those convenient spray sunscreens, try holding your breath or breathe out when applying. Inhaling the nanoparticles of zinc or titanium in the spray can be harmful to lungs, says the Environmental Working Group. Also, don't forget to rub in the spray to ensure full coverage.
Another FYI, because physical sunscreens use zinc oxide and titanium dioxide, two white minerals, they can sometimes leave behind a chalky white finish on the skin think of the white on surfers' noses. If you have a fair to medium skin tone, this might not be a problem once you work the sunscreen in. But for those with dark skin tones, it might be an issue. Look for lotions that say "clear" or "tinted" on the label.
Weight Loss. United States. Type keyword s to search. Today's Top Stories. Taraji P.
0コメント