What You Need To Know About Sun Protection

What is the difference between SPF 30 and 50?

Sun protection factor (SPF) directly measures protection against sunburn caused by UV B rays. A SPF 20 sunscreen means that it absorbs 95% of UVB rays, while an SPF 50 product can block 98%.

A practical example is that if you take 10mins to burn in the sun, SPF 20 increases that 20 times to result in sunburn of the same intensity (so 200 minutes), SPF 50 increases that 50 times (500 minutes). Generally I advise people to reapply sunscreen every 2 hours when in the sun. About 1/4 to 1/2 of people studied do not apply sunscreen adequately, so they are not receiving the right level of protection. 

Does SPF 30 gives double the protection of SPF15?When looking at SPF we are not only concerned with how much UV radiation is blocked, but also how much UV can be transmitted onto our skin to cause damage.

Sunscreens with SPF 15 (blocks 93% of UVB rays) allows 7% of UV radiation to hit our skin. Sunscreens with SPF 30 (blocks 97% of UVB rays) allow 3% of UV radiation to hit our skin.
Put simply the UV transmission rate is cut by around half. Therefore SPF 15 is half as effective as SPF 30 at allowing UV penetration through to the skin.

Does sunblock block 100% of UV rays?

Sunblocks usually contain titanium dioxide and zinc oxide. The term sunblock gives the impression that it can totally protect you from the sun, which is untrue and has led to that term being banned by the FDA. People use the term sunblock and sunscreen interchangeably.

Tell me about vitamin D and skin?

Sunlight helps our body to produce vitamin D through the skin. The amount of sun exposure required for this to occur safely without increasing the risk of sun damage is difficult to quantify. It depends on several factors, like your skin type, location, time of day and weather. It is also difficult to determine how long would be needed for a person to make the daily recommended amount of vitamin D.

To ensure adequate vitamin D levels, diet and supplements are good sources. Vitamin D fortified foods include yoghurts, margarine and cereals, oily fish is naturally rich in vitamin D.

Small amounts of incidental sunlight that you get through daily activities may help to boost your vitamin D levels; just exposing your face, forearms, hands, lower legs should be enough.

If you are at high risk of skin cancer (fair skin, personal or family history of skin cancer, more than 50 moles, on immunosuppressants), you should protect your skin in the sun, and aim to get vitamin D from diet and supplements like multivitamins or cod liver oil.

Can I use an antioxidant instead of sunscreen to protect my skin from UV damage?

Infrared radiation penetrates deeper than UVA rays to cause sun damage and aging by producing free radicals. Antioxidants may counteract this, but importantly they do not offer protection against UVA (implicated in skin ageing) or UVB (implicated in skin cancer).

Actually I recommend both. A good way to apply them is to layer your sunscreen over the antioxidant serum.

How often should I reapply sunscreen?

I normally advise reapplying sunscreen every two hours at least or more often if you are physically active (e.g. sweating, using a towel after swimming or exercising or making physical contact with anything that might rub it off), even if the bottle claims four-hour water resistance. Remember most people do not apply sunscreen adequately in the first place so re-application is useful to cover those missed spots.

Should I reapply sunscreen if I am working inside?

If you work indoors and sit away from windows, you may not need a second application. Monitor how often you are going outside though, even if for a short walk. It might be helpful to keep extra sunscreen in your workspace just in case.

The ultraviolet light that penetrates through windows is UVA light. This is responsible for causing signs of skin aging. Check the level of UVA cover in your sunscreen. Make sure it gives you broad-spectrum or UVA protection (4 and above).

The safest method is to apply sunscreen daily as part of your skincare routine, regardless of whether you plan to be outdoors or not. Your skin will thank you!

Is my skin safe from UV behind glass?

UVA can penetrate window glass and penetrates the skin more deeply than UVB.UVB rays damage the top layers of your skin, causing sunburn. Both UVA and UVB can cause skin cancer.
UVA radiation is associated with skin ageing. It breaks down collagen and elastin in the skin and leads to wrinkles, leathery skin and pigmentation.

UVA protection in a sunscreen will help defend the skin against photo ageing and potentially skin cancer.

Does skin of colour need sun protection?

Melanin is the most important pigment determining skin colour. Human skin contains 2 types of melanin: eumelanin and pheomelanin. Eumelanin is brown to black pigment, pheomelanin is a red or yellow. Pheomelanin is predominant in light skin, blond or red hair. Eumelanin offers more protection from the sun than pheomelanin and is present in pigmented skin. Darker skin colour therefore has more natural sun protection but recommendations regarding sun protection (e.g. clothing, shade and sunscreen) should be used during periods of prolonged or intense sun exposure.

In addition, cases of skin cancer in people with darker skin are often not detected until later stages, when it is more dangerous. So appropriate protection and self-monitoring are just as important as people with lighter skin types.

Can I get skin cancer if my skin never burns?

Sun exposure without skin protection can be harmful anytime and anywhere, especially during the peak hours of 11am-3pm in summer. Just because you do not get sunburn does not mean you are protected against skin cancer. Sadly there is no such thing as a healthy tan. Any change in your natural skin colour is a sign increased melanin production in an attempt to prevent further damage. The evidence suggests tanning greatly increases your risk of developing skin cancer.

Can my self-tan protect me from the sun?

Most self-tanning products don’t protect your skin against the harmful effects of the sun on their own. I recommend applying a broad spectrum sunscreen with an SPF of 30 or over whether your skin is self-tanned or not. Remember to reapply during periods of intense or prolonged sun exposure. Never substitute proper sun protection.

If you enjoy the look of a tan or sun-kissed skin, as many people do, self-tanning at home can deliver the same psychological boost without the dangerous UV exposure of sunbathing.

Can I occasionally use a indoor tanning bed?

Remember having a tan is a sign of skin damage caused by UV rays from the sun. Every time you tan or burn, you damage the DNA in your skin. The more you damage your DNA, the greater your risk of getting skin cancer.

There is sadly no such thing as a safe tanning bed/booth/lamp. The bulbs used in tanning beds emit mostly UVA light, which is associated with signs of skin ageing as well as skin cancer. In addition, indoor tanning is associated with side effects like burns, loss of consciousness, and eye injuries.

If you do want a tan for a special occasion, it is a much better idea to visit a salon for a spray tan or DIY with sunless tanning products.

Can people become addicted to tanning?

Studies show that some people who tan have symptoms of addiction . The prevalence of tanning addiction ranges from 4% in the general population to 33% among frequent indoor tanners. Self-tan is safer option!

Images by Martin Vorel and Beate

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