All About SPF

Sunscreen for outdoors

All About SPF

We’re blessed to live in a country like sunny Australia, but life in a sunny place comes with a few extra precautions that we must take in order to protect our skin, such as wearing sun protection (SPF). Being proactive and preventing exposure to the sun’s UV rays is the best way to beat the burn, and there are two main types of sun protection on the market (PHYSICAL and CHEMICAL) that can help with this battle! A good sunscreen is the most age-preventative product on offer so it’s important to choose the right one that fits into your everyday lifestyle and one that you won’t think twice about using, so let’s run through some SPF details that you must know about: 

UVA/UVB Rays

The general rule of the thumb is that we should be wearing sunscreen as soon as we are exposed to any form of natural light. Rain, hail or shine, UVA rays are constantly around us every single day of the year and due to the longer wavelength they are particularly notorious for causing premature ageing in our skin. They can even penetrate through glass windows – yes, this also applies to all of you “I don’t wear sunscreen as I work in an office” offenders! All of those small trips to and from the shop and driving your car can very much contribute to sun damage that could’ve easily been avoided. 

UVB rays are a much shorter wavelength and are responsible for turning us into tomatoes through the burning of our skin. It causes instantaneous DNA damage to our cells which can lead to an array of skin cancers. Although our ozone layer can filter some of the UVB rays, a lot still manage to pass through. 

A sunscreen which is labelled as ‘Broad Spectrum’ means that you are protecting your skin from both UVA and UVB rays. This is something you should absolutely consider when buying any sunscreen.

So what actually is SPF?

SPF (sun protection factor) by definition, is a relative measure of how long a sunscreen will protect you from ultraviolet rays. We use the equation below to work out how long an SPF will last according to Australian standards:

Take the time you would normally burn in the sun without protection (around 20 minutes of sun exposure will normally start to produce redness).

Multiply this number by the SPF of your product. Example: with an SPF 15 x 20 minutes of sun time = 300 is how many minutes you can stay in the sun without burning.

Getting physical vs. chemical

Physical Sunscreen

A physical sunscreen is made up of either zinc oxide or titanium dioxide, or sometimes both. As we know, zinc is a very restorative, therapeutic mineral which makes this type of SPF a good option for sensitive skin types. It’s also a great sunscreen to use after a resurfacing skin treatment and one that we often recommend in the clinic post treatment is Cosmedix Hydrate +. This type of protection activates instantly when it’s applied to the skin so there’s no need to wait before stepping outside and exposing yourself to UV. You could look at physical sunscreen as kind of like a shield of protection, since it literally blocks and reflects any UV rays that it comes into contact with. Those who are prone to acne may be better suited to this type of sunscreen, as both ingredients are non-pore clogging. This type also tends to be the version we recommend to our clients who have Melasma, as we know this type of pigmentation is triggered by heat and by using a physical sunscreen, we reduce the amount of heat seeping in. It is said that zinc oxide has better UVA protection and less free radical damage as opposed to a chemical sunscreen, however there isn’t any concrete evidence on this. 

Will a physical sunscreen containing zinc oxide give me a white face?

You may have seen surfers, cricket players and tradesmen with white noses. What they are wearing is a physical sunscreen, however that’s not to say all physical sunscreens will give us a white face. A durable but cosmetically elegant physical sunscreen will most likely contain some tinted spheres that blend to our own skin tone. Although this sunscreen is known for its thicker consistency, there are some excellent primers and moisturisers we stock that can be hydrating or mattifying and spread over the skin really well.

Note:

You may not be able to use this type if you have allergies to zinc oxide or titanium dioxide. If you are a swimmer or someone who sweats a lot, this may not be ideal since it is only water resistant for up to 40 minutes. 

Chemical Sunscreen

Chemical sunscreens have been given a bad rap over years for many different reasons, and it feels like physical sunscreens have been the more popular choice, BUT there is definitely a time and place for chemical sunscreens as long as it’s one from a reputable, cosmeceutical-based brand with top quality ingredients (Avobenzone, Oxybenzone or Octinoxate are common ones). 

Chemical sunscreens have a longer water resistance duration and tend to be a bit more lightweight than their physical counterparts, and are better absorbed and layer more nicely with other products. This makes chemical a more suitable option for people who are active or work outside. Make-up that also advertises SPF protection usually contains a chemical SPF filter, although I would never solely rely on make-up alone for sun protection as it’s not strong enough to prevent sun damage.

A chemical sunscreen works by using chemical filters to absorb UV rays into our skin, and then breaks down the UV by converting it into heat and releasing it from our body. For this reason you usually have to wait 20-30 minutes for the product to start working. 

The downside

Hormone activity, coral reef destruction and skin allergies have been linked to chemical sunscreen ingredients but there’s currently not enough information to say that these ingredients cause any harm, so when tested through the FDA they have in fact been approved for our use. There are some formulations which minimise or reduce the chemical filters in the ingredients as well as using plenty of antioxidants in the mix, so with this in mind my opinion is that using a quality chemical sunscreen is going to be better than using no sunscreen at all! 

Final tip

Avoid using cheap body chemical sunscreen on your face as most likely it will contain preservatives and reactive chemicals that can cause allergies and irritation. Always opt for sun protection specifically developed for the face, whether it is physical or chemical. 

 

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