International Regulatory & Scientific Consulting, Paul-Lincke Strasse 36, 67304, Eisenberg, Germany.
Photochem Photobiol Sci. 2010 Apr;9(4):495-509. doi: 10.1039/b9pp00180h.
Based on the current weight of evidence of all available data, the risk for humans from the use of nano-structured titanium dioxide (TiO(2)) or zinc oxide (ZnO) currently used in cosmetic preparations or sunscreens is considered negligible. There is a large body of information that when viewed in its entirety is considered as sufficient to demonstrate that these nano-structured ultraviolet (UV) filters, irrespective of various treatments (coatings) or crystalline structure, can be regarded as safe for use at concentrations up to 25% in cosmetic products to protect the skin from harmful effects of solar UV radiation. "Nano" TiO(2) and ZnO formulated in topically applied sunscreen products exist as aggregates of primary particles ranging from 30-150 nm in size. These aggregates are bonded such that the force of sunscreen product application onto the skin would have no impact on their structure or result in the release of primary particles. Multiple studies have shown that under exaggerated test conditions neither nano-structured TiO(2) nor ZnO penetrates beyond the stratum corneum of skin. Further, the distribution and persistence of these nano-structured metal oxides is the same compared to larger pigment-grade (i.e., >100 nm) particles, demonstrating equivalence in the recognition and elimination of such material from the body. Finally, the in vitro genotoxic and photogenotoxic profiles of these nano-structured metal oxides are of no consequence to human health. Whereas the most logical, straightforward conclusion based on data from internationally-recognized guideline studies and current 20+ year history of human use is that nano-structured TiO(2) and ZnO are safe, there will continue to be questions as "nano" conjures images of technology gone awry. Despite this rather sober view, the public health benefits of sunscreens containing nano TiO(2) and/or ZnO outweigh human safety concerns for these UV filters.
基于现有所有可用数据的证据，目前在化妆品制剂或防晒霜中使用的纳米结构二氧化钛（TiO2）或氧化锌（ZnO）对人类的风险可忽略不计。有大量信息表明，综合来看，这些纳米结构紫外线（UV）滤光剂足以证明，无论经过何种处理（涂层）或晶体结构，在化妆品产品中浓度高达 25%时都可以安全使用，以保护皮肤免受太阳紫外线辐射的有害影响。配方为纳米 TiO2和 ZnO 的局部应用防晒霜产品以尺寸为 30-150nm 的初级颗粒的聚集体形式存在。这些聚集体是键合的，以至于防晒霜产品涂抹在皮肤上的力不会对其结构产生影响，也不会导致初级颗粒的释放。多项研究表明，在夸大的测试条件下，纳米结构 TiO2和 ZnO 都不会穿透皮肤的角质层。此外，与较大的颜料级（即>100nm）颗粒相比，这些纳米结构金属氧化物的分布和持久性相同，表明在从体内识别和消除此类物质方面具有等效性。最后，这些纳米结构金属氧化物的体外遗传毒性和光遗传毒性特征对人类健康没有影响。虽然基于国际公认指南研究的数据和目前 20 多年的人类使用历史得出的最合理、最直接的结论是纳米结构 TiO2和 ZnO 是安全的，但由于“纳米”让人联想到技术出错的形象，仍会存在一些疑问。尽管有这种相当冷静的看法，但含有纳米 TiO2和/或 ZnO 的防晒霜对公共健康的益处大于对这些 UV 滤光剂的人类安全担忧。
