Sunscreen Information

Noel Coward famously lamented the typical British behaviour when in sunnier climbs with his song line; "...mad dogs and Englishmen go out in the midday sun". This tongue-in-cheek send up of the British colonialists was written in 1932, and delights at the seemingly mad, yet understandable practice of sun worshipping by a nation whose favourite topic of small talk is often how much rain we have been having lately.

But have we changed much in the last 70 years?...

We all know that we should wear sunscreen before we even embark on hitting the beach with our bucket and spade, unless we want to come home looking like the proverbial lobster; but what sun protection will you take with you this summer and how many of us use a sunscreen daily as recommended?

You need only turn on the television most summers to find competing sunscreen adverts by big names such as L’Oreal, Nivea, Ambre Solaire, Piz Buin and Boots Soltan telling us why we should buy their brand over all others; but how do you know what you really should be looking for?

SPF, UVA, UVB? Is it all too confusing? If the answer is yes, you're not alone. Our recent survey of 100 UK consumers (88 female and 12 male), primarily in the age range of 32 – 52, highlights the ever present need for the education of consumers in understanding sunscreens and their use.

Only 50% of those surveyed regularly use a facial moisturiser which contains sun protection, yet dermatologists recommend DAILY use of a broad-spectrum (covering a wide range of wavelengths) UVA and UVB sunscreen with a Sun Protection Factor (SPF) of at least 15, as the most effective way to protect the skin from photodamage - skin ageing caused by exposure to the sun.

So what does that actually mean, and how many of us are not as sunscreen savvy as we might think?

Sunlight arrives on Earth in three forms; infrared (heat), visible light and ultraviolet radiation (UVR) in the form of UVA (315 to 400 nm wavelength), UVB (280 to 315 nm wavelength), and UVC (100 to 280 nm wavelength) rays. However, UVC rays don’t actually reach the Earth as they are filtered out by the Ozone Layer; hence we need only really worry about UVA and UVB rays for the time being.

UVA light penetrates deeper into the skin than UVB light and is thought to be a prime cause of photoageing; characterised by wrinkles, dark blotches, freckles, leathery skin and a loss of skin elasticity. 99% of the ultraviolet radiation that reaches the Earth's surface is actually UVA, yet deceptively we mostly hear about worries concerning UVB radiation, as it is this form that causes the visibly noticeable “tan” and “sunburn”.

As a natural defense against UVR, the body, depending on the skin type of the individual, tans when exposed to moderate levels of UVR by releasing the brown pigment melanin. This helps the skin to block the penetration of the UV rays by absorbing the UV light, and prevent damage to the vulnerable tissues deeper down.

However, sunburn occurs when the exposure to UV light exceeds that of the protective capacity of a person's melanin. Melanin content varies greatly but in general darker skinned people have more melanin than lighter skinned.

Sunburn is usually not immediately obvious. After being burnt, skin may turn red 2 to 6 hours later, with pain at its worst 6 to 48 hours afterwards. The burn continues to develop for 24 to 72 hours after the incident and skin peeling begins 3 to 8 days after the burn occurs. The major danger of sunburn however is the increased risk of future skin cancer such as melanoma.

One of the interesting and generally little known things about UVR is that it is reflected by different surfaces. These reflections can amplify the effects of UV exposure. For example, snow reflects 90% of UV light; which is why you can get snow blindness and severe sunburns from skiing on a sunny day. Sand can also reflect up to 20% of UVB light that hits it, meaning that you can get extra UV exposure at the beach.

Pleasingly, in our survey only 6% of people admitted to regularly sunbathing, whilst 61% stated only occasional sun worshipping and a healthy 33% never sunbathe at all.

With the advent of commercial sun bed salons on every high street, and recent media stories of “tanorexia”, the addiction to visiting these UV producing machines; we were pleased to note that our survey revealed that it seems the message about the dangers is finally getting through, with no one admitting regular use and 74% stating that they never use sunbeds.

88% of people knew that their skin would age more quickly if they spent time in the sun, yet the Western attitude towards the desirability of having a tan still persists, with over 60% of people agreeing that having a tan makes then look healthier and more attractive. However, with the results above suggesting a move away from sunbathing and sunbed use, it was no surprise to note that over half of people regularly or occasionally resort to fake tanning products to give them the desirable result without the damage caused by UV exposure.

Sunscreens or sunblocks that partially block UV radiation are widely available and display a Sun Protection Factor, often abbreviated to SPF, which is a measurement of protection against the UVB rays, which cause tanning and sunburn.

A sunscreen rated as SPF15 blocks 93.3% of UVB radiation and one with SPF30 blocks 96.7%.

Therefore, for example, a sunscreen with an SPF15 will protect your skin from harmful UVB light up to 15 times longer than if you wore no protection on your skin at all.

Our survey highlighted that even this most basic of sunscreen facts was not as widely known as it should be, despite it being written on most available sunscreen bottles. We found that 24% of people were unable to identify the correct meaning of SPF15; with 8% believing that they were to reapply sunscreen every 1.5 hours; 9% believing it meant they could sunbathe on each side of their body for 15 minutes without burning, 4% believing they were protected from sunburn for 15 hours; and most worrying of all 3% thinking that they would just tan without burning at all by using an SPF15 sunscreen.

Dermatologists recommend that the sunscreen you use should have a SPF of at least 15 and should be applied half an hour before going outside and reapplied every two hours thereafter to give you the stated protection. It should also be reapplied after prolonged swimming or vigorous activity where you have been sweating.

Our survey found that although a worrying 14% admitted to using no sunscreen at all, the majority of people (66%) were thankfully using a sunscreen with an SPF within the range of 11 to 30.

Crucially though, according to recent research people may be far less protected than they might think.

SPF is tested and rated in the laboratory as 2mg/cm2 of sun cream applied to the skin, but studies suggest that in reality people only apply 0.5mg/cm2 or less; that’s only 20-25% of the amount used to determine the SPF value written on the label. (1) Some experts have therefore questioned the current SPF testing methods, stating that they need to be changed to reflect actual average application of sun cream.

In addition to this discrepancy between testing methods and actual use, recent findings also suggest that the SPF you read on the bottle may not be the same SPF as contained inside. In July 2004, researchers at Which? magazine tested 15 leading sun creams, from high street chemists Boots and Superdrug and others from cosmetics firms, including Simple and Nivea, all stating SPFs of between 15 and 30. They found that some provided less protection than they claimed, while others did not block out damaging UVA rays as effectively as they claimed. However, both the manufacturers and the chemists denied these findings, claiming Which?’s testing methods were unreliable and misleading.

However, in addition to Which?, the Trading Standards Institute (TSI) carried out it’s own research and tests in June 2004 at an independent laboratory on children's protective products, and found that almost 90% failed to provide the protection claimed; leading them to urge government to bring in tough new legislation for the sunscreen industry. Of eight sunscreen products tested, marketed at babies and children, three of the products failed to live up to their UVA star rating, while four others did not match the claimed SPF.

The TSI has therefore issued its key recommendations for tighter regulations presented to the Department of Trade and Industry and to European commissioners, which include:

• Standard tests on a sun product’s SPF, UVA and water resistance.
• Only approved test laboratories to carry out sun screen testing.
• Regulations on how a product can be described, including a restriction on statements alleging a product offers ‘complete protection’ or ‘sun block’.
• An upper limit on a product’s SPF of 30 or 30+. The extra sun protection offered above 30 is minimal.
• A mandatory ‘best before’ date on all products sold solely for sun protection. This information is rarely provided.
• Clear instructions on bottles and packaging for product use and storage.
• We still await any change in SPF testing standards.
  

As we have already discussed, UVA light has a longer wavelength than UVB and can therefore penetrate deeper into the skin, making it the prime cause of skin ageing; along with tissue damage, mutation, and skin cancer as seen with UVB exposure.

Due to this longer wavelength it is also able to penetrate through glass windows and can still affect the skin, such as when driving a car. This was highlighted in studies looking at American truck drivers, who tend to drive with their windows wound up in air conditioned cabs, who showed more extensive photodamage on the left side of their faces, (the side nearest the window).

As UVA penetrates deeply it does not cause sunburn like UVB light. This causes a problem for scientists as the fact that UVA radiation does not cause reddening of the skin like UVB means it cannot be measured within the SPF testing; hence there is no standard international measurement for the blocking of UVA radiation, despite it being important that sunscreens block both UVA and UVB.

In fact, 24% of people we surveyed admitted that they didn’t know whether UVA and UVB filters were an important consideration in their choice of sunscreen, a confusion possibly emphasised by a lack of a widespread standard measurement.

However, a (4 star) UVA star rating was created by Boots the Chemist in 1992 for use in the UK, which has since been adopted by most leading sunscreen manufacturers to become the basic industry standard recognised worldwide. This current system for rating UVA protection was updated in February 2004 and goes from 1 star to 5 stars, representing a ratio of UVA protection relative to UVB protection, the SPF. It is recommended that you always look for a sunscreen with the maximum star rating.

The UVA wavelength range is further split up as UVA1 (340–400 nm) and UVA2 (320–340 nm) and recent scientific studies have revealed that it is the longer wavelength UVA1 rays that cause photoageing as they penetrate deepest into the tissues of the skin (2). However, most sunscreens currently available in high street shops do not protect against UVA1, despite promoting themselves as having generic “UVA filters” to prevent ageing etc.

With the availability of higher SPF rated sunscreens, meaning individuals will spend larger amounts of time in the sun without burning from the UVB rays, concerns have now been raised within the medical community as to the adequacy of the comparative UVA protection contained in these products; as people may be subject to greater UVA exposure and damage than if they stayed out for a shorter period of time with a lower SPF product.

Our survey revealed that whilst 64% of people stated that they always bought a sunscreen containing a UVA filter; of that same group only 28% always bought one claiming a UVA1 and UVA2 filter, with 15% saying that they never even checked for both filters.

Given what we have highlighted above, it is not surprising to find that in our survey, 83% of people are confused about which sunscreen to buy to help protect their skin against the ageing effects of the sun.

Recent studies show that the most commonly used sunscreen ingredients protect mainly against UVB rays which cause sun burning, and not UVA rays that cause photoageing.

In fact only Zinc Oxide blocks all three, UVB, UVA1 and UVA2 rays. This is often seen on cricketer’s and lifeguard’s noses as white “war paint”; hence traditionally restricting its use as an all over body cover due to the white tint it leaves. However, manufacturers are now developing transparent zinc oxide products in order to make them more cosmetically desirable and to give that total body protection.

The sunscreen industry splits sunscreen ingredients into two categories, chemical and physical (mineral) filters. Chemical filters which absorb the UV rays are typically absorbed by the skin and are thought to be metabolized by the body, sometimes causing allergic reactions in some individuals; (although there is no real clinical data established for this to date). Physical or mineral filters which reflect the UV rays lie on top of the surface of the skin and are not absorbed by it or metabolized by the body. Many manufacturers normally combine chemical and physical ingredients to enable them to provide the range of protection on offer; some ingredients to look out for are below.

Ingredients to look for when shopping for sunscreens

Bibliography
(1) Sunscreens used at the beach do not protect against erythema: a new definition of SPF is proposed.
Wulf HC et al. Photodermatol Photoimmunol Photomed. 1997 Aug;13(4):129-32.

Quantity of sunscreen used by European students.
European Organization for Research and Treatment of Cancer Melanoma Co-operative Group. Br J Dermatol. 2001 Feb;144(2):288-91.

(2) Quantitative assessment of cumulative damage from repetitive exposures to suberythemogenic doses of UVA in human skin.
Lavker RM, Veres DA, Irwin CJ, Kaidbey KH. Photochem Photobiol. 1995 Aug;62(2):348-52. Related Articles, Links

Sunscreens can cause irritant contact dermatitis, allergic contact dermatitis and also photo-allergic contact dermatitis in some people.
 
Photo-allergic dermatitis differs from allergic contact dermatitis, as the rash occurs only after the skin comes into direct exposure with the combination of the allergic substance (in this case the sunscreen ingredients) and sunlight.
 
Some people are allergic to the chemical ingredient Para-aminobenzoic acid (PABA), so many sunscreens are now PABA free.
 
If you suspect that you have a sunscreen allergy you should consult a dermatologist for a skin patch test. After the patch test, they should be able to advise you on the type of sunscreen that you can use and which to avoid.
 
Sunscreens can also "go-off", so it is recommended to not use out-of-date sunscreens left over from previous holidays as they lose their effectiveness at protecting you from the UV radiation. Most sunscreen packaging will carry a "use by" date.

A wide variety of sunscreen products are available from the High Street, beauty salons and clinics; making purchasing sun protection products very confusing.
 
As skin types vary, visiting a skincare specialist or dermatologist will help you establish exactly which sun protection products are best suited for your skin.

Prices for suncreen products can range from £2.00 to £40.00+ depending on the type and brand.

In order to protect the skin from photodamage, dermatologists recommend daily use of a broad-spectrum UVA and UVB sunscreen with a Sun Protection Factor (SPF) of at least 15; yet as we have seen from our survey consumers are still confused when it comes to purchasing adequate sun protection for their skin.

In the UK, sun creams currently have to comply with cosmetics safety laws contained in the Cosmetics Products (Safety) Regulations 1996, which also cover general beauty products. However, these regulations do not include a method for determining SPF (UVB protection) or UVA protection values, and do not give guidance about what claims can or cannot be included in labelling; all helping to explain why there is no universal system or standards and consumers are left in the dark.

As the research into the effects of UVA light continues and the unfortunate rise in skin cancer cases accelerates, more and more manufacturers are looking at ways to offer a proper broad-spectrum sun protection product that actually does what it says on the label.

So before you step out of the front door this summer, make sure you choose a sunscreen that offers the protection you need and liberally slather it on. As always though, sun avoidance still remains the most desirable form of protection from the sun.