SPF stands for “sun protection factor,” which is a measure of how long a topically applied product will protect you from the sun’s UVB rays skin (if the topical product exactly as directed by the manufacturer). For example, using an SPF30 means that it will take 30 times longer for your skin to burn than it would do with no sunscreen applied. SPF 15 blocks 93% of UVB rays, SPF 30 blocks 97%, and SPF 50 blocks 98%.
BROAD SPECTRUM means that your sunscreen provides protection from both UVA and UVB radiation. An easy way to distinguish what exactly these are responsible for in human skin is:
U V A (A = Aging) rays penetrate deeper into the skin where it damages collagen and elasticity of the skin and causes photo-ageing. UVA rays penetrate through glass / windows. UVA radiation plays a role in the formation of certain types of skin cancers.
U V B (B = Burning) rays are shorter rays and causes burning of the skin, DNA damage, a breakdown of collagen, elastin and other structural components of the skin. Such damage is visible as sun spots (lentigos), pigmentation, wrinkles and loss of elasticity. UVB rays play the most significant role in damage that may lead to sun burns and skin cancers.
Both UVA and UVB rays have overlapping negative effects (both can cause trauma and DNA damage and premature / photo-aging).
TWO MAIN TYPES OF SUNSCREEN
- Mineral (physical) Sunscreen: Formulated primarily to block, scatter and reflect the UV rays, before they penetrate the skin. Due to larger molecular size of ingredients, it does not get absorbed into the skin, but rather forms a barrier on top of the skin. Usually a thicker consistency, and may leave a white cast due to ingredients such as zinc oxide, titanium dioxide, mica, etc.
- Chemical Sunscreen: Contains chemical filters and is formulated to absorb UV radiation before they can damage the skin, chemical sunscreens blend into the skin. Normally lighter formulations and easier to apply. Usually contains avobenzone, octisalate and homosalate.
OPTIONS FOR YOUR PREFERENCES
- Gel-Based Sunscreen: New generation lightweight formulations in the form of a gel which absorbs into the skin seamlessly.
- Tinted Sunscreen: Comes in a variety of shades, contains pigments to match various skin tones and conveniently eliminates the need for foundation.
- Reef safe Sunscreen: Studies have shown the adverse effects of chemical sunscreens on the health of the oceans and sensitive reef systems. Some popular dive destinations have banned sunscreens that isn’t explicitly labelled “Reef Safe”
HOW MUCH IS ENOUGH
Sunscreen can only protect your skin if it’s applied correctly. For the face & neck, use about half a teaspoon of sunscreen per application. For the entire body, a shot glass full of sunscreen per application is recommended. Remember to re-apply every two hours when outdoors and even more when swimming / sweating.
WHY IT MATTERS
A whopping 80% of skin’s ageing is a direct result of UV radiation (sunburn). Exposure to UV radiation increases your risk of skin cancer. If you have fair skin, a family history of skin cancer or any other sun exposure risk, you should definitely use a much higher SPF. The highest SPF being SPF 100 which blocks out about 99% of UVB rays. This is recommended for those with very fair skin, a history of sun damage or skin cancers, albinism and other genetic disorders that may prevent the skin from protecting itself from UV radiation.
Photoaging (premature ageing) of the skin is a direct consequence of repeated sun exposure, characterized by wrinkles and loss of elasticity. This is caused by the breakdown of collagen and other structural components of the skin.
Excessive exposure to UV rays can also suppress the immune system, reducing the skin’s ability to protect against various pathogens and potentially leading to an increased risk of infectious diseases.
SPECIALISED SUNSCREENS FOR SKIN CONDITIONS
For sensitive skin, mineral sunscreens containing zinc oxide or titanium dioxide are less likely to irritate the skin. Fragrance-free and hypoallergenic products should be non-negotiables. Individuals with oily or acne prone skin should opt for sunscreens that are oil-free and non-comedogenic. Gel-based or water-based sunscreens are both good options.
Whilst a sunscreen with a lower SPF will do just fine when you’re mostly indoors, a formula with a higher SPF should be applied for days when more time is spent outdoors. For people who have a history or higher risk of skin cancer, existing pigmentation or genetic diseases such as albinism or certain immune disorders, an even higher SPF is recommended.