When you walk past a shelf in a beauty store, you will see tons of sunscreens on display. Choosing the perfect sunscreens is a crux of a matter especially when you read all the ingredients listed at the back label of sunscreens. Taking into consideration which sunscreen provides broad-spectrum protection against UVA and UVB radiations or in other words, which sunscreens offer the best and the most protection.
So, the first thing to know is that sunscreens can be divided into two types: chemical sunscreens and physical sunscreens
Chemical sunscreens are synthetically derived and they work by sinking into the skin and absorb the harmful radiation before converting them into heat and “deactivating” them in the dermis layer. Oxybenzone, octocrylene, octinoxate and avobenzone are examples of active chemical filters in the sun care.
And, physical sunscreens or sunblock consist of two main active ingredients; titanium dioxide, zinc oxide or a combo of those two to form a barrier on top of the skin to scatter the UV radiation from penetrating deep into the skin.
Photo 1: Colorescience.com
We’ve covered what titanium dioxide is, in our previous blog, check it out here. Today, we will be discussing about Zinc Oxide.
Zinc oxide is the metal zinc that has been oxidized which comes in white –colored powder that has been used as medicines for centuries. It has been used as a healing salve to treat an open wound and been added into calamine lotion to treat diaper rash. Today, zinc oxide also used widely in food products, bandages and sunscreens.
Based on Photo 1, it shows zinc oxide is the broadest spectrum reflector for both UVA (320-400 nm wavelengths) and UVB (290-320 nm wavelengths) and it works right after application and it doesn’t break down in the sun.
When you apply sunscreen and it appears to have a white, opaque, powdery cast on your face and body, that could most probably contain zinc oxide as its main ingredients. But with the latest technology, zinc oxide is micronized so that it comes in a smaller particle and appear clear upon application. Its better isn’t it?
According to Melanie D. Palm, (M.D) San-Diego based dermatologist, people with sensitive skins, rosacea and acne patients can used zinc oxide and its anti-inflammatory properties benefits those people. In fact, zinc oxide also blocks out visible and infrared light that will aggravate pigmentary problems in patients with skin discoloration and melisma.
Regarding health concerns, FDA has listed zinc oxide as generally recognized as safe (GRAS) and can be used as a colorant in food industry and cosmetic industry as well as in some medicines. Besides that, FDA stated that zinc oxide is used in over-the-counter (OTC) skin protectants and anorectal skin protectant drugs with a concentration of 25 percent.
The Environmental Working Group suggests that zinc oxide is one of the safest sunscreens ingredients to be used and it is rated 2-4 in which depends on the usage of the zinc oxide itself.
The Cosmetics Directive of the European Union also approved the use of zinc oxide as a colorant and be labelled as CI 77947. They regulated that zinc oxide as safe for dermal application in its uncoated and non-nano form and must restricted to that application in which it will not lead to the exposure of the end-user’s lung. In 2016, the EU published a new amended regulation in which it includes that zinc oxide in its nanoparticle form can be used as a UV filter in ready-to-use cosmetic products. Zinc oxide in its non- nano and nanoparticles form can be used up to 25 percent as individually or in combination and restricted to a dermal application to avoid any exposure to the consumer’s lungs.
However, applying sunscreens does not stop you from the exposure of these dangerous UV rays but it decreases the risk of developing squamous cell carcinoma by 40 percent and melanoma by 50 percent. And most importantly it prevests premature skin aging. Seek shade, wear a wide-brimmed hat and wear outfits with UV protections is other ways to prevent sunburn.