How long do I have to be in the sun before I develop a sunburn or suntan?
Very fair people may burn in midday sun even after only 10 to 15 minutes. When you lie in the sun your skin will soon start to become pink. This is thought to be due to the heat or infrared action on the skin. This is less visible in darker skins.
If you have olive skin it may take 20 to 30 minutes sun exposure to produce the delayed sunburn.
In other words, a sunburn is a delayed effect following sun exposure that may not appear for six hours and will not peak for 24 hours following sun exposure. This is why it is so important to be proactive and use sun protection from the beginning of your sun exposure on any day.
A suntan starts after a few days and is an attempt by the skin to partly protect itself from more sun damage. It is another sign the skin has been damaged by the sun.
Why do I need to protect my skin from the sun?
The main reasons to protect your skin from sunlight are to reduce the effects of the sun on the skin, which can include acceleration of normal ageing i.e., premature skin ageing - wrinkles, skin sagging and sunspots. Also, several types of skin cancers are caused by sunlight. These are mostly on the increase including melanoma skin cancer which must be diagnosed early to reduce a fatal outcome.
Why is sunlight harmful to the skin?
Sunlight that reaches the earth surface consists of two main parts, the shorter wave length are known as UVB which is responsible for sunburns. Sunburns are always more severe in fair skin but may occur with any colour of skin. UVB is also a major cause of skin cancer. Most skin cancers can often take 20 years after the initial sun damage to appear, i.e. somebody with a lot of sun exposure in their teenage years may not start to show skin cancers until their mid 30s or 40s. This delay is known as the latent period, i.e. the time it takes to develop a skin cancer after the sunlight damage. A Melanoma often has a much shorter latent period.
The other part of the sunlight spectrum is UVA. UVA is mainly responsible for ageing of the skin. It penetrates to the deeper parts of the skin and damages the support structures known as collagen and elastin. This damage gradually leads to wrinkling and sagging. UVA also causes darkening or pigment patches on the skin known as sunspots (sometimes wrongly called liver spots).
It can also lead to damage to the small blood vessels in the skin, which results in spider veins on the face, neck and chest. UVA reaches the skin all year round including the winter months. It also goes through glass including most car windows and is present on cloudy days as well as sunny days.
What is SPF?
Most sunscreens around the world will have an SPF number.
What does SPF mean?
The SPF is an abbreviation for Sun Protection Factor, which can be as little as five or as high as 100. Example, if you were the person with the very light skin who sunburns after 10 minutes in the sun you could stay in the sun for a 15 times longer i.e., 15 x 10 = 150 minutes or two and a half hours with an SPF 15 sunscreen.
If you were the person with the olive skin, who takes 20 minutes to develop a sunburn or suntan you could use the same sunscreen for 20 x 15 = 300 minutes or five hours.
How do I know how my skin will react?
As a rough guideline, your skin type is based on your history of past exposure to sunlight.
Skin phototype 1 - You will burn very easily and rarely or never tan. You are most likely to have red, very light blond hair and freckles. Any attempt at tanning in phototype 1 is very harmful and unsuccessful.
Skin phototype 2 - If you have skin with this type you will always burn but will gradually tan, if you use sunscreens and expose gradually to sunlight. You have fair skin and usually blue eyes and blond or light brown hair.
Skin phototype 3 - You have a light olive skin usually with brown or green eyes and dark hair. Skin will burn if overexposed but you will develop a medium to dark tan when exposed gradually to the sun even with a sunscreen.
Skin phototype 4 - This is a darker olive colour usually with brown eyes and dark hair. You may burn slightly but you will always tan deeply and relatively quickly.
Skin phototype 5 - Your skin is brown to light black usually with brown eyes and dark hair. Sunburn looks minimal and the skin tans briskly and deeply.
Skin phototype 6 - This is darker black skin with brown eyes, dark hair. The skin does not easily show sunburn and tans very deeply.
Skin phototypes 2 to 6 have more efficient and protective type of pigment or melanin than redheads.
Also, skin phototypes 4, 5 and 6 may not see very much sunburn redness because of their skin colour. However, they do experience some burning after sun exposure. Their skin ages with wrinkles and brown sunspots but they do have a reduced chance of skin cancer compared to phototypes 1 and 2.
How are sunscreens presently tested?
They are mainly tested at the moment for their Sun Protection Factor (SPF) value. This test is summarised as follows.
On day one, a volunteer's skin is exposed to a powerful lamp called a sun simulator to see how long it takes for the lamp to produce sunburn. This will be at its maximum between six hours and 24 hours after the brief sun exposure.
On day two, small dabs of sunscreen are applied to the lower back or in forearms (i.e., areas usually least exposed to the sun). The powerful sunlamp simulates the sun as UVB and UVA rays are shone for usually 5, 10, 15, 20 or 30 times longer than was shone on day one. 24 hours later these areas are again checked for sunburn.
The area that closely matches the sunburn redness from day one, i.e. without a sunscreen, is the area that has been protected by the sunscreen for the amount of time that the sunlamp was shone on the skin e.g., 5, 10, 15, 20, 30 times on day one. The sunscreen will therefore have an SPF of 5, 10, 15, 20, 30 etc.
Dr Lowe's supercharged daily protective cream is an SPF 15. This means that the sunlamp, (sun simulator) shone on volunteer's skin for 15 times longer than day one and protected the skin.
There will always be a slight sunburn or suntan with any sunscreen no matter how high the sun protection factor, as sunscreens are not complete blocks. For example, an SPF 15 sunscreen will protect you against 93% of the burning rays of the sun.
An SPF 30 protects just 4% more than an SPF 15, i.e. 97% against the burning rays.
In other words a high SPF does not give much more protection than SPF15. For regular daily protection SPF15 is ok.
Why did the European Union change the sunscreen regulation?
Sun Protection Factor testing is done in a laboratory using a powerful sunlamp for a few minutes only. However, most people are out in the sun for much longer periods and many were burning despite only being in the sun for shorter periods of time and the laboratory testing predicted that they could be with their sunscreen.
It was discovered that some of the actual ingredients in the sunscreens were deteriorating after longer sunlight exposure than had occurred in the laboratory, i.e. They were not stable in sun.
How stable are sunscreens?
Sunscreens may be broken down by sun exposure so they no longer protect your skin. New tests have been designed to make sure that a sunscreen does not get too damaged by the exposure to sunlight and it can be considered stable.
Briefly the sunscreen is exposed to high levels of sunlight from the sun simulator and repeat SPF and UVA testing is performed. If there is no reduction in SPF number then the sunscreen is stable.
What future labelling will sunscreens have?
They will be labelled as below:
SPF 14.9 or below low protection
SPF 15 - 30 medium protection
SPF above 30 high protection
SPF above 50 very high protection
What About UVA Protection?
They will also be labelled with a UVA logo, which confirms that the UVA protection is at least one-third of the protection against UVB. Some stores, such as Boots The Chemists, may continue to use their star rating for UVA protection.
Who is at extra risk from sun damage?
- Fair skin
- Red hair
- Blonde hair
- A family history of skin cancer
- Your own previous skin cancers
- Multiple moles
- Previous severe sunburns in the past or ultraviolet treatments for any skin diseases such as acne or psoriasis, any radiation treatment for cancers.
A daily sunscreen is vitally important for these people as well as the routine use of sun protective hats and clothing.
For people who are extemely sun sensitive it might be worth getting ultraviolet plastic coating applied to car windows.
How much sunscreen should I apply?
There is a general rule that sufficient sunscreen to cover the face would be the amount of sunscreen that would cover the upper part of your first and middle fingers i.e. put the sunscreen along the back of the first two fingers and apply that to the face. Two finger cover is about one flat teaspoon full. You need the same amount for the neck and the same amount to the upper chest and the same amount to the back of both hands.
What about sunscreen and vitamin D?
Reducing the sunlight that reaches the skin can sometimes reduce how much Vitamin D your skin can produce. Vitamin D is needed for healthy bones and may reduce some types of cancers e.g. prostate, breast, bowel cancer.
Use a daily sunscreen and take a Vitamin D oral supplement daily. Vitamin D3 capsules may be the most effective types for you.
What SPF number sunscreen do I need to use?
The simple suggestion is the following: For all skin colours on a normal working day or a day where you spend time walking to the office, driving your car, walking with your children or dogs, in the UK a sunscreen with an SPF 15 in the new terminology (medium protection) plus with UVA protection is sufficient.
This should be applied over the exposed skin of the face, neck, upper chest and hands in the morning after the skin has been dried following your bath or shower. Women can put make-up over this after five minutes drying.
An SPF 15 sunscreen will protect you against 93% of the burning rays of the sun providing it is applied sufficiently.
If you have fair skin i.e. you burn easily and tan slowly, have red hair, blonde hair, blue eyes then if you are going out for more than four hours on a mid summer's day in Northern Europe or are in a sunnier part of the world e.g. Florida, Caribbean, Mauritius, Maldives, New Zealand or Australia then you should apply a sunscreen that is specifically tested to be an SPF 30 with UVA protection. It should be water resistant or waterproof. If you are swimming, exercising, perspiring and wiping your skin you need to reapply this sunscreen after each of these.
If you have olive skin or darker skin then an SPF 15 with a UVA protection is more than sufficient for you to apply wherever you are in the world.
Sunscreens higher than a 30 are of doubtful value, as the degree of protection does not increase exponentially and only can go up to about 98% maximum protection.
When do I need extra protection e.g sun protective clothing?
Sunscreens are a vital part of your overall skin sun protection programme. However, if you are outdoors a lot during the mid summer months in Northern Europe or the other sunny places it is very wise to use additional sensible precautions.
These include very sunny days between the hours of 10:00 a.m. and 2:00 p.m., so always try to sit in the shade.
If you are walking on a golf course, playing tennis etc. through the middle of the day, always wear a hat that throws shadow over the face and neck.
If you are exposed to the sun in sunny climates excellent sun protective clothing can be obtained. The reason for this is that some normal golf or tennis shirts and T-shirts only have protection factors as little as SPF 5, which means that you can get sun damage through those shirts. Specially designed sun protective clothing with textiles that protect against much higher levels of sunlight often above 50 equivalent SPF is very effective for protecting the body.
Sunscreen Myth 1:
Adding another layer on top of an existing layer of sunscreen doubles the sun protection factor.
TRUTH: This does not happen - two layers of an SPF 15 sunscreen remains an SPF 15 and does not become an SPF 30.
Sunscreen Myth 2:
Water resistant and waterproof sunscreens do not have to be reapplied.
TRUTH: If you are swimming, showering and then wiping your skin dry, waterproof or water resistant sunscreens will resist removal more than other sunscreens but still need reapplication to maintain their optimum SPF value.
Sunscreen Myth 3:
Sunscreen should not be used on children.
TRUTH: This is true for young children under the age of six months, as these young children can get very good sun protection with sun protective prams, hoods, sun protective clothes, blankets and umbrellas, i.e. keep your little one in the shade where possible. From the age of six months onwards babies can be protected with sunscreens in addition to the above protective measures. Use sunscreens that are labelled as formulated for children.
Sunscreen Myth 4:
The higher the Sun Protection Factors, the better.
TRUTH: It is not necessary to use Sun Protection Factors higher than 15 for daily use. A 15 protects against 93% of sunlight reaching the skin. An SPF 30 protects against 97% of sunlight reaching the skin, i.e. only 4% more than an SPF 15.
A very high SPF can make it very difficult for the manufacturer to protect adequately against UVA (the ageing rays) as the SPF refers only to UVB protection. You therefore may be exposing yourself unknowingly to large amounts of UVA during the day. UVA rays carry the risk of skin ageing, increased brown sunspots, pigmentation and some skin cancer.
Dr Lowe applies SPF15 every day. If he is outdoors for several hours on a very sunny day in a very sunny climate, he uses a water resistant SPF30 sunscreen, plus between 10am and 3pm he uses sun protective hats and clothing. He still enjoys the outdoors - but he is protecting his skin.
Sunscreen Myth 5:
Preparing the skin with sunbed treatments can help to protect the skin.
TRUTH: These lamps produce very large amounts of UVA, much greater than the UVA you are exposed to in the most intense sunlight. This amount of UVA carries all the risks (melanoma, other skin cancers, severe skin ageing) to a much greater degree than UVA from sunlight. Avoid all suntanning lamps.
Sunscreen Myth 6:
Sunless skin tanning gives sun protection.
TRUTH: If you want to have tanned skin use a sunless tanning lotion, gel or spray that contains Dihydroxyacetone. This skin tan does not however give any relevant sun protection by itself and it is very important that you use your daily sun protection recommended above. It is not a "real tan" but rather a superficial colour of the outer layer of skin.
What parts of me need special protection?
Areas often sun damaged and not sun protected include the neck, the back of the hands, the front of the chest. It is very important to remember to apply sunscreen to these areas.
New European sunscreen labelling will show the SPF number as low, medium and high. Low - SPF up to 14.9, medium SPF 15 to 29.9, high SPF 30 to 49.9, very high SPF 50 above.
For the sunscreen to have a UVA protection label it must be shown to protect against at least one-third of the UVB or SPF number.
In addition, at Boots the Chemists stores you will also find the very helpful UVA star rating system. My recommendation for daily use is a medium protection, SPF 15, that is stable with protection.