請問，我買了一瓶薇姿的隔離霜，它的Mexoryl SX, Terephthalylidene Dicamphor Sulfonic Acid 為3.960%，是否已達2/5的危險指數?謝謝
Mexoryl SX是较新的一种紫外线UVA防晒剂，皮肤吸收率低，获得了美国FDA的认可。不过，Mexoryl SX吸收紫外线的波段并未涵盖所有UVA波段，而且曝露在阳光下两小时即可分解40％，所以常常需要搭配其他防晒剂一起使用。
Mexoryls SX formulations always showed a higher protective potency than sunscreen without it even when the protection against erythema was similar (products with same SPF). Mexoryls SX formulations also prevented or significantly decreased to minimal, ferritin, tenascin and lysozyme expression induced by repeated UVA or SSR exposure. It also reduced the enhancement of collagenase 2 mRNA expression induced by SSR exposure. Finally PMLE study demonstrated that UVA protection was essential for the prevention of this photodermatose.
CONCLUSION:
Mexoryls SX formulated in sunscreens or daily use products have been shown to be an effective UV absorber, leading to an increased efficacy of these products against a large number of biological damage induced by UVA, SSR or sun exposure.
https://www.ncbi.nlm.nih.gov/pubmed/18717957
Between 2003 and 2010, sunscreen makers applied for FDA permission to use eight sun-filtering chemicals developed by European companies. Four of these – Tinosorb S, Tinosorb M, Mexoryl SX and Mexoryl XL – appear to be more effective than avobenzone, the most common UVA filter permitted by the FDA. The FDA’s failure to respond to these applications prompted Congress to pass the Sunscreen Innovation Act of 2014 (FDA 2014). This act requires the FDA to review new applications for sunscreen active ingredients within 300 days, but it doesn’t relax the standards companies must meet to prove new ingredients are both safe and effective.
https://www.nytimes.com/2005/06/09/style/skin-deep-psst-this-stuff-keeps-you-young-but-its-illegal.html
Found in chemical sunscreens
Mexoryl SX is a UV filter used in sunscreens and lotions across the globe. It has abilities to block UVA1 rays, which are the longwave rays that spur skin aging.
A 2008 reviewTrusted Source showed it’s an effective UV absorber and ideal for preventing sun damage.
While this ingredient has been in European circulation since 1993, the FDA didn’t approve this ingredient for L’Oréal until 2006. Medically, it’s been approved for adults and children over 6 months of age.
Fast facts
Approved in: United States, Australia, Europe, Japan
Banned in: None
Best for: Sun damage prevention
Coral safe? Yes
https://www.healthline.com/health/beauty-skin-care/best-sunscreen-ingredients#mexoryl-sx