The lowdown on sunscreen; SPF ratings, UV and more

The lowdown on sunscreen; SPF ratings, UV and more

If there is one thing we’ve noticed over the years, it’s the confusion that exists around sunscreens. From SPF ratings to the different types of UV rays and best before dates, let’s take a closer look and separate some sunscreen myths from the facts.  

So, what  exactly  is UV?    

The sun's emissions include UV, visible light, heat and other radiations. As visible light can be divided into colours which we can see in a rainbow, UV is subdivided and commonly defined as UVA, UVB and UVC. UVC doesn’t penetrate our atmosphere, so it isn’t of concern to our skin. Let’s focus on those pesky rays that do cause the most concern to our skin health – UVA and UVB   

Are UVA and UVB rays the same?

UVA rays are what cause your skin to tan. They are also the cause of premature skin ageing, uneven skin tone and hyperpigmentation and can heighten your risk of skin cancer. About 95% of the UV rays which reach our skin are UVA, and they are present even on cloudy days. They are often considered silent offenders as unlike UVB, you cannot feel them impacting your skin.  

UVB rays are the major cause of sunburn and just like UVA also increase your risk of skin cancer. They burn the more superficial outer layers of the skin. If your skin has become red after sun exposure, or you notice discolouration or other changes to your skin’s surface, UVB is going to be the culprit.  

How does unprotected sun exposure damage my skin?

UV rays penetrate beyond the surface of the skin and damage the collagen fibres. This damage results in your body producing abnormal elastin and degraded collagen, which leads to your body making mistakes when it rebuilds your skin. As this continues to occur, the incorrectly rebuilt skin begins to form wrinkles, while the depletion of collagen causes it to become “leathery.”  

UV rays can also trigger excess melanin production as the skin attempts to protect itself causing uneven splotches of colour commonly known as hyperpigmentation. This can occur in all skin tones even those with a higher melanin content where there is sometimes the misconception that less UV protection is necessary.   

In addition to the more cosmetic side of sun damage to the skin there is undisputed evidence that shows that as UV rays penetrate, they can cause mutations that lead to skin cancer.  

I’ve heard the term UV index – what is that?   

Back in 1992, Canadian scientists developed a scale known as the UV index. It measures the likelihood that UV radiation will cause your skin to burn, which means it is measuring UVB rays. Health officials recommend you should apply sunscreen if you are going to be outdoors when the UV index is at 3 or above. Finding out what the UV index is on any given day is quite easy – in Australia you can find this information by checking the UV forecast on the Bureau of Meteorology website or app.  

What about Vitamin D?

When our skin is exposed to UV rays, our bodies use this to create Vitamin D, which helps us to regulate calcium levels in our blood and to keep our bones, muscles and teeth healthy. There is a myth that wearing sunscreens which protect us against UV rays can cause us to become deficient in Vitamin D. Yes, in lab conditions, sunscreen has been shown to decrease Vitamin D production. But in a laboratory environment there are no UV rays from the sun! When put to the test in real world circumstances, it has been proven to have very little impact on Vitamin D production.    

So how can we protect ourselves and still enjoy the great outdoors?

Where possible consider the time of day when you’re outside. Try and limit exposure to early morning and late afternoon on summer days.   

Wear sunglasses and wide-brimmed hats to decrease ocular exposure.    

Cover up. Wear loose-fitting, closely woven fabrics that cast a dense shadow when held up to the light.   

Adequately apply and reapply a broad-spectrum SPF.

SPF  

Now we understand the differences between the two main types of UV rays and that we need protection for our skin, let’s delve into the confusing world of SPF.  

The first thing to know is that to protect against both UVA and UVB rays, you are going to need a broad-spectrum sunscreen.  Broad-spectrum sunscreens provide protection against both UVA and UVB rays helping to reduce your risks of sunburn, premature ageing, and skin cancers. To do this, they will contain a combination of different ingredients protecting against different types of UV.  

There are different SPF ratings which measure the amount of time the sunscreen you’re using will protect you from UVB rays before your skin starts to burn. It also gives an indication of the percent of UVB rays it can screen you against.  

The most common SPF ratings in Australia are:  

SPF 15: Blocks 93% of UVB rays. Takes 15 times longer for UV rays to begin burning your skin, as compared to bare skin. Great for your average day at the office with a few outdoor errands.  

SPF 30: Blocks 97% of UV rays. Takes 30 times longer for UV rays to begin burning your skin, as compared to bare skin. Great for if you’re going to be outdoors a bit more.  

SPF 50: Blocks 98% of UV rays. Takes 50 times longer for UV rays to begin burning your skin, as compared to bare skin. Great for days when you’ll be spending a lot of time outdoors.  

How much sunscreen do I need and how often should I apply?  

When SPF testing is conducted, the sunscreen has been applied “liberally”. Unless you can say the same of your application method, you’re not going to get the full benefits of the sunscreen you have applied. The Cancer Council recommends an average adult will need one teaspoon of sunscreen each for their face and neck, each limb, the front and the back of the body. That’s about 35ml for a full body application.  

It is also of utmost importance that you continue to re-apply sunscreen during the day if you are out and about. The Cancer Council recommend you do this two hourly and after you have been swimming or sweating excessively. We know how easy it is to forget to do this when lapping up a glorious day at the beach or enjoying a midday BBQ with friends at the park! Perhaps try setting a reminder on your phone if you think you need it.  

How long can I keep my SPF product for?

Did you know that sunscreen goes out of date? If the tube you’ve just dug out of the bottom of your beach bag from last summer is past its best before, get a new one! Sun protection is serious business (if you haven’t already gathered from this lengthy and informative overview), and you don’t want to risk the health of your skin with a product that can no longer provide you with the protection you deserve.  

The Australian-made factor

The UV levels reaching our ‘sunburnt’ nation are higher than those affecting Europe or North America, and thanks to Australia being physically closer to the sun during our summer months, we can end up being exposed to as much as 15% more UV.  

Because of this Australia has stricter standards for sunscreens than anywhere else in the world, meaning that an Australian sunscreen is going to give you some of the best protection possible. To tell if the sunscreen you are looking at is Australian, look to see if it has an AUST L number.  

At Alpha-H, we are dedicated to skin health and helping our customers to age on their own terms which is why we have created products for daily use which contain broad-spectrum sunscreen. These allow us to help you both protect and nourish your skin in one simple step.

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