What does SPF mean?
We know its important but what does it all mean? 🤔
Sunscreens usually have an SPF rating. 15, 30 or 50. SPF stands for sun protection factor. In Australia, its considered a comestic only when the SPF is less than SPF 15 and is not the main function (e.g marketed as a make up). Otherwise its considered therapeutic good governed by the TGA. In many parts of the world, it's considered a drug too. 🥼
SPF means how long you can stay in the sun without burning. If you are fair, you could probably only stay in the sun 15mins before you burn. If you add SPF 30plus, that means you can stay in the sun 30 times longer. 15 x SPF 30 = 450mins or 7.5 hours. Obviously don't count sweating or going into the water and is only a rough guide. 🏊🏖🌝
Then there's UVA and UVB. What does that mean? 🤔
UVA = those rays that penetrate deeply into the skin causing premature aging.
UVB = produce the sun burn ☀️
UVA rays are present all your round so thats why its important to use sunscreen all year round. Sunscreens by law, must provide at least 1/3 UVB coverage when they are formulated. ☀️ ♨️
There are chemical sunscreens and then there are physical sunscreens
Physical sunscreens are zinc oxide and titanium dioxide which are naturally occurring. They are used to reflect UV light by blocking entry onto the skin.
They are a thick, white and very chalky material. To make a natural Spf 30+, approx 50% of chalky material is needed. To stabilise this in a formula, a decent amount of oil is needed. Which explains why natural sunscreens can present as greasy and ghosts on the skin. Its the nature of the raw materials were working with.
FORMULATING A SUNSCREEN:
As sunscreens as governed by the TGA, they must be tested in an independent sunscreen lab. Sunscreens are tested on willing humans and developing a sunscreen costs thousands for a company. Its no easy tasks and a process which takes a long time.
HOW MUCH TO APPLY:
2mg per 2cm of skin.
Approx. half a teaspoon 🥄
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