SPF is one of the most important skincare ingredients for every skin type. If left unchecked, ultraviolet (UV) rays from the sun can cause an array of skin problems, from accelerated signs of aging to skin cancer. However, many people do not know what SPF exactly means and what SPF number to use.
In this blog post I will explain the details of how much to use, broad-spectrum, chemical vs. physical sunscreens and much more.
ULTRAVIOLET A (UVA)
contributes to skin cancer risk and is recognised as the age-accelerating ray because it’s always present. It’s also known as the allergy ray and can stimulate allergic reactions within the skin.
ULTRAVIOLET B (UVB)
is a short wavelength that varies in strength throughout the year (peaking in the summer), and can also burn and age the skin.
Even on cloudy or overcast days you should be applying sunscreen daily to exposed areas, such as the face, as UV rays can still pass through cloud and reach the Earth’s surface causing damage to our skin. UVB levels are lower in winter, so the risk of sunburn, tanning and skin cancer is lower, while UVA rays – which contribute to skin ageing, dark spots and skin cancer – are relatively constant throughout the year.
Use SPF30 as your minimum, SPF50 is preferable. SPF50 also gives a higher level of protection against UVA rays, so think about your skin in terms of preventing ageing, not just cancers.
How Much Sunscreen Do You Need to Use?
Many people do not apply enough to reach the SPF number listed on the bottle. You must use at least ¼ teaspoon of SPF on your face and about a shot glass on your body in order to get the proper amount of SPF.
Re-apply! If you use a moisturiser containing SPF 15 (for example) at 8am in the morning, if you would normally burn in 15 minutes of sun exposure, technically you should be reapplying your SPF at 11.45am (someone wearing SPF 15 can be exposed to 15 times the amount of UVB light than someone wearing no SPF at all before redness will occur). Reapply sunscreen at least every hour after swimming or sweating profusely. Ensure you cover ears, sides of face, décolleté, back of neck (short hair or ponytail).
The EU has also reclassified sun protection ratings
Low = 6-14 Medium = 15-29 any type of ethnicity that tans easily and rarely burns High = 30-50 fair, Caucasian, ‘pale’ Very high = 50+ If you are a redhead. Redheads with freckles have phaeomelanin – opposed to the rest of us that have eumelanin. You’ll burn easily, quickly and the damage will be long-lasting.
If you use an SPF in the low-medium category you will tan.
If you don’t want any colour at all you need to use 30 and above and reapply frequently.
Use a separate SPF after your moisturiser
A moisturiser or tinted moisturiser containing SPF frequently only protects from UVB, it does not protect you from UVA. Also, SPF moisturisers are less likely to be rub-resistant. If you then apply your makeup with fingers or a brush or perspire – it’s gone.
If you’re wearing make-up, an SPF in a mist form is great because you can easily apply it on top without affecting your make-up. SPF formulas with a tint are perfect for people who like a more natural look.
Chemical vs. Physical (Mineral) Sunscreen
There are two main types of sunscreens: chemical and physical. Chemical sunscreens work by absorbing UV rays, then converting them to heat. This prevents the UV rays from penetrating the skin and causing cellular damage. Chemical sunscreen ingredients such as oxybenzone and octinoxate have recently come under fire for possibly causing damage to coral reefs and having unwanted hormonal effects on the user. Another ingredient commonly found in chemical sunscreens, avobenzone, can cause stinging and irritation.
Physical (Mineral) sunscreen works by creating a physical barrier between your skin and UV rays. These fine particles reflect the UV rays off your skin, preventing them from penetrating the skin and causing damage. Physical sunscreens do not come with chemical sunscreen risks, but they can be less spreadable and may leave a white film on the skin (although it disappears after 5 minutes) Zinc Oxide and Titanium Dioxide are the active ingredients used in most physical sunscreens.
What Does “Broad-Spectrum Sunscreen” Mean?
If you want proper protection from the sun you need to use a broad-spectrum sun protectant cream – a dedicated product that’s sole purpose is to protect your skin from the damage the sun does to it.
There is currently no standard of measurement in the United States that applies to UVA protection and the five star round UVA symbol is for example not required in Australia. This is why you want to look for sunscreens that say they offer “broad-spectrum protection” which includes both UVA and UVB protection.
UVB light is responsible for the superficial symptoms of a sunburn that you see, such as redness and peeling.
UVA light, on the other hand, can penetrate deeper into the skin, causing accelerated aging, dark spots and skin cancers. This is why it is crucial that your sunscreen offers both UVA and UVB protection. If you make sure to get good protection and also have sensitive skin, buy SPF aimed at children from dermatologist brands. They are nearly always fragrance-free and high in SPF.
Always buy fresh every year. SPF in the bottle degrades in the sun and heat, don’t carry it over to your next break