To start, we think it is important to clarify that both mineral and synthetic sun protection can protect skin against harmful UVA and UVB rays.
How does mineral sun protection differ from synthetic sun protection?
Mineral sun protection works completely differently from synthetic protection. Mineral protection uses minerals - zinc oxide and/or titanium dioxide - which sit on top of the skins surface creating a protective ‘shield’ over the skin. These minerals instantly reflect the sun’s rays before they can penetrate the skin’s surface, so you can enjoy the sun immediately after applying. In comparison, synthetic sun protection is absorbed into the skin. After 20-30 minutes the sun protection becomes effective and, through a chemical reaction, will absorb UV rays and then convert them into heat which is then dissipated from the skin.
In both instances your skin is protected from UV rays. However, with synthetic sun protection before the chemicals can offer any UV protection your skin first has to absorb them which can cause irritation, reactions (like prickly heat) and extreme discomfort.
What ingredients are used in mineral sun protection and synthetic sun protection?
All mineral SPF’s will contain either zinc oxide, titanium dioxide or both which sit on top of the skin reflecting UV rays. Some brands now combine mineral protection with synthetic chemical enhancers to boost the SPF, however a certified natural or organic sun protection product, such as our ORGANii products as well as brands such as lavera, Weleda and eco cosmetics, will be formulated with natural SPF boosting ingredients such as avocado oil, coconut oil, almond oil, karanja oil and carrot seed oil to reach the desired factor. Some brands who use synthetic enhancers can still claim to be organic as the word is not regulated for use on skincare products the same way that it is strictly regulated for food, so if you’re not sure, look for a natural or organic certification label from an independent certifier on the bottle because these manufacturers really care.
Synthetic sun protection products typically include between two to six active chemical ingredients, the most common being Oxybenzone and Octinoxate. Because these sunscreens are absorbed by the skin before they can become effective, these chemicals can cause skin inflammation, irritations and rashes and can disrupt hormones in both men and women.
EWG (Environmental Working Group) test chemicals for their hazard level and rates them from 1 (Best) to 10 (Worst).
Oxybenzone: 6-8 - “Oxybenzone is a sunscreen ingredient associated with photoallergic reactions. This chemical absorbs through the skin in significant amounts. It contaminates the bodies of 97% of Americans according to research by the Centers for Disease Control and Prevention.” - EWG
Octinoxate: 5 - “This common sunscreen ingredient is shown to have hormone-mimicking effects on laboratory animals. This chemical is found in humans, including mothers' milk samples.” - EWG
These chemicals not only effect our bodies but our environment too. In 2018 the governor of Hawaii passed a bill into law that banned the sale of all sun products that contain Oxybenzone and Octinoxate on all Hawaiian islands as they are known to damage coral reefs and fish.
What Sun Protection Factor do I need?
Each skin type has its own natural protection time and without the appropriate sun protection you should not stay in the sun longer than this. Using a sun protection factor (SPF) prolongs the time you can stay in the sun without running the risk of getting sunburn. The following formula can be used as an approximation of how long it is safe to stay in the sun.
Skins own protection time x sun protection factor
For example, if you have fair skin that (without sun protection) allows you to stay outside in the sun without getting burnt for 10 minutes this means;
10 mins x SPF15 = 150 minutes (2 hours and 30 minutes)
10 mins x SPF20 = 200 minutes (3 hours and 20 minutes)
10 mins x SPF50 = 500 minutes (8 hours and 20 minutes)
This formula can be applied to all sun protection factors.
It is important to re-apply sun cream during this time however once you have reached your sun exposure limit it is advisable not to expose skin any longer even if more SPF has been applied.
Remember that for all sun protection, the SPF is a measure against the protection of UVB rays (not UVA rays). It is important to choose a broad-spectrum product which protects against UVA rays also.
It is also important for us to note here that an SPF30 does not give double the protection of an SPF15, in fact the increase in protection is only around 5%. We explain this in more detail a bit further down the page.
What is the difference between UVA and UVB rays?
Ultraviolet light, or UV light, is light from the sun that is not visible to the naked eye. There are three types of UV light, UVA, UVB and UVC. However UVC light, which is short-wavelength, is filtered by the atmosphere and does not reach the earth's surface, so we shall only focus on UVA and UVB lights here.
UVA light is long-wavelength. This means that the rays penetrate deep into the skin. These rays, which are associated with premature ageing of the skin, can cause damage to the elastin and collagen fibres which make skin supple and firm, causing a loss of tightness, can assist the development of free radicals and can cause permanent harm to DNA. While it was believed that it was UVB rays (not UVA) that can cause the development of skin cancer, the World Health Organisation (WHO) has stated that they no longer believe this to be the case;
“For a long time it was thought that UVA could not cause any lasting damage. Recent studies strongly suggest that it may also enhance the development of skin cancers.” - WHO
UVB light is medium-wavelength. These rays penetrate the top ‘superficial’ layers of skin and are the main cause of sunburn. They do significant damage to the DNA at the heart of the skin cells and significantly promote the development of skin cancer.The sun protection factor (SPF) is what protects against UVB rays.
A product with SPF15 will block about 92% of UVB radiation.
A product with SPF20 will block about 95% of UVB radiation.
A product with SPF30 will block about 97% of UVB radiation.
A product with SPF50 will block about 98% of UVB radiation.