Mineral sunscreen vs chemical sunscreen. What should I choose?
By Estival Life (8 May 2018; Updated on 16 May 2019)
On 1 May 2018, the Hawaii state legislature passed a bill that would ban sunscreen products that contain oxybenzone and octinoxate with effect from 2021. These chemicals are found in many popular sunscreens and are linked to hormone disruption in people and the bleaching of coral reefs and coral death. The government of Republic of Palau also announced in April 2019 to be the first country enforcing this prohibition with effect from 1 January 2020.
The harm of these chemicals are also found in Hong Kong. A study by Hong Kong Baptist University (HKBU) released in October 2018 has detected an extensive amount of sunscreen chemicals in seawater that could pose a risk to human health. The study also revealed that these contaminants are commonly found in the coastal waters of Hong Kong.
Oxybenzone can cause allergic skin reactions and, according to the Centers for Disease Control and Prevention, it is detected in the blood of more than 96 percent of Americans. It is even found in breast milk. A recent study found that adolescent boys with higher oxybenzone levels had significantly lower total testosterone levels. Octinoxate is an endocrine disruptor that mimics estrogen, but more research is needed on this chemical.
“The Hawaii ban calls attention to the fact that the sunscreen market is flooded with products that use potentially harmful ingredients and provide poor UVA protection,” said Environmental Working Group (EWG) President Ken Cook.
Most of the best-scoring beach and sport sunscreen products in the EWG Guide to Sunscreens are mineral-based, using zinc oxide and titanium dioxide to filter harmful radiation.
Sunscreen is indeed a unique body care product: consumers are directed to apply a thick coat over large areas of the body and reapply frequently. Thus, ingredients in sunscreen should not be irritating or cause skin allergies and should be able to withstand powerful UV radiation without losing their effectiveness or forming potentially harmful breakdown products. People can potentially inhale ingredients in sunscreen sprays and ingest some of the ingredients they apply to their lips, so ingredients must not be harmful to lungs or internal organs. Further, sunscreens commonly include ingredients that act as “penetration enhancers” and help the product adhere to skin. As a result, many sunscreen chemicals are absorbed into the body and can be measured in blood, breast milk and urine samples.
Active ingredients in sunscreens come in two forms, mineral and chemical filters. Each uses a different mechanism for protecting skin and maintaining stability in sunlight. The most common sunscreens on the market contain chemical filters. These products typically include a combination of two to six of the following active ingredients: oxybenzone, avobenzone, octisalate, octocrylene, homosalate and octinoxate. Mineral sunscreens use zinc oxide and/or titanium dioxide. A handful of products combine zinc oxide with chemical filters.
Laboratory studies indicate that some chemical UV filters may mimic hormones, and physicians report sunscreen-related skin allergies, which raises important questions about unintended human health consequences from frequent sunscreen application.
There’re also many misconceptions about sunscreen products. Below FAQ list some common ones:
Q1) Is SPF no. proportional to the sun protection?
A: Nope! The Sun Protection Factor (SPF) was advocated to indicate how well your product protects you from UVB, which is the sunburn ray. But it does not measure how well a sunscreen will protect from UVA rays, which are also damaging and dangerous.
Q2) What is the percentage of UVB that’s blocked from your skin compared with your product’s SPF value?
A: SPF 2 means 50% of UVB rays are blocked
SPF 4 means 75% of UVB rays are blocked
SPF 10 means 90% of UVB rays are blocked
SPF 15 means 93% of UVB rays are blocked
SPF 30 means 97% of UVB rays are blocked
SPF 50 means 98% of UVB rays are blocked
SPF 70 means 98.5% of UVB rays are blocked
SPF 100 means 99% of UVB rays are blocked
Q3) How sunscreens work?
A: Organic / Chemical sunscreens absorb into your outer dead skin cell layer and use a chemical reaction to block UV rays from passing farther into your skin. (NOTE: The term ‘organic’ doesn’t mean natural, it means not mineral.) You feel this reaction as warmth, which is why organic sunscreens may make you feel a little extra hot in the sun. The organic chemicals break down during this sun blocking chemical reaction, which is why sunscreen products tell you to reapply every 2 hours when you’re out in the sun.
Mineral / physical sunscreens sit on top of your skin and bounce the sun off, without a chemical reaction and without creating the warmth. Mineral sunscreens include zinc oxide and titanium dioxide. Years ago, mineral sunscreens were white on the skin. Today’s modern versions are made with high-tech formulations so that the mineral particles don’t clump together. Instead, they distribute evenly and invisibly over your skin surface. They also don’t pass into your skin and thus are good for people with sensitive skin and even babies. Meanwhile they don’t readily break down when they block the sun so their sun protection last longer on your skin.
Remember, you have to put the correct amount of sunscreen on for this protection. Plus, organic / chemical sunscreens break down as they block the UV rays. Mineral sunscreens are structurally more durable and can last longer on your skin.
UVA protection is also critically important for anti-aging and skin cancer prevention because UVA:
Look for a product labeled Broad Spectrum to be certain you are also getting good UVA protection. Also find a product formulated with at least 5% or more zinc oxide because:
Dermatologist recommended people to use 2 types of zinc oxide sunscreen products (one water resistant for sweaty and wet outdoor activities and one with a more matte finish for everyday use).