All about ‘sunscreens’

The term, ‘suntan’ lotion, may be commonly used by many to describe a sunscreen product.

However, the purposeful use of a sunscreen product is to protect you from the suns rays that cause a suntan.

This basic principal may help focus your view, on the roll of ‘sunscreens’, for protection rather than to promote the idea of getting a suntan.


It is of course good advice to cover up, wear a hat, sit in the shade or avoid the mid-day sun wherever possible, however, there will be times when your skin is exposed to the sun and this is where the use of sunscreens has an important roll to play.

Sunscreens, depending on their type, will absorb or reflect a proportion of the suns UV rays. It is important to note that no ‘sunscreen’ will totally block all of the suns rays.

There are two types of rays that you will need protection from; UVB and UVA. It is important to select a ‘sunscreen’ product that offers protection from both of these rays.

UVB protection - There is an internationally recognised standard for the measurement of UVB absorbance, you will recognise this by the SPF rating shown on all ‘sunscreen’ products.

Important note: SPF ratings are only in relation to UVB rays

Below is a diagram that demonstrates the absorbance levels of UVB rays. The diagram shows the SPF category in accordance with the percentage of absorbancy.

It is interesting to note that SPF 15 will absorb upto 93.33% of UVB rays whereas
SPF 30 will only add a little over 3% greater absorption than SPF 15.

UVA protection - There is no internationally recognised standard for the measurement of UVA absorbance.

However, here in the UK, we do have an Industry recognised standard; the UVA star rating system. Most leading brands subscribe to this system under license from Boots The Chemist Ltd, when selling their products in the UK.

This can be recognised by the indication of a UVA star rating symbol, normally shown on the reverse side of the product. These range from one to five stars. Five star being the highest protection against UVA.

This system includes a scientific test protocol that measures the ratio of UVA/UVB absorbance for the sunscreen product. This is then used to allocate the appropriate UVA star rating category.

In Australia they have a different system. This is called Australian UV-A Standard.
Under this system there is also a scientific test protocol, this may be described in broad terms as follows:-

UV-A protection is recognised when a sunscreen preparation transmits, between a wavelength of 320nm and 360nm, less than 10% of the incoming light.

In many other parts of the world, the term ‘broad-spectrum UVA’ is generally used.

There is mounting pressure on Governments and the World Health Organization to agree on an international standardised measurement for the absorbance of UVA and to introduce a symbol or mark to be easily identifiable by people, rather like the SPF rating used to identify UVB protection.

Development of sunscreens & SPF ratings

We live in the 21st century, where technological advances are astounding. We therefore expect both Governments and scientists to have all the answers to all of our questions.

However, the development of ‘sunscreens’, their test protocol and our in-depth knowledge of the dangers of the sun’s UV rays are relatively new.

The advent of the package holiday and the desire to have a tanned skin are relatively new in our times, especially in scientific terms, where research takes on many different aspects and this can take decades to prove findings.

The skin has an immediate response to overexposure to the sun. Prolonged periods without protection will result in sunburn. This is evident within a matter of hours. UVB rays are the culprits. From this simplistic view you may understand that initially protection from the sun’s UVB rays became a priority.

People are enjoying more outdoor activities, taking holidays in hotter climates and ‘sunscreen’ products were originally designed to protect you from sunburn. This gave birth to the ‘SPF rating’ system which has an internationally agreed test protocol, to determine the SPF values.

However, although sunburn is dangerous and can be seen immediately, there are more dangerous aspects to overexposure, which take time to take effect. This includes skin cancers and premature ageing of the skin. Since skin has such an important job, to protect our body from the harmful effects of the environment, premature ageing is not merely a cosmetic look. Good healthy skin will protect the body more efficiently.

Skin cancers usually result from the accumulative effect of overexposure to UV light over a number of years. Many only appear in later life. However, the most deadly and aggressive form of skin cancer – melanoma – is found in young people. The incidence rate for this cancer in young people is rising alarmingly.

There is mounting scientific research that UVA rays are now linked to this disease, premature ageing of the skin and potentially other forms of skin cancer.
This is why the World Health Organization is working to gain an internationally agreed standard for the optimal method for specifying protection against broad-spectrum UVA.

You may appreciate that although UVA sunscreens have been available for a number of years, research into this field is more recent than for UVB. The accumulative effect of overexposure is naturally more recent than the initial sunburn effects. This is in a nutshell why currently there is no internationally recognised ‘SPF’ type rating for UVA.

Important note:

We have explained earlier that in many countries the loose term ‘broad-spectrum UVA’ is generally used. When purchasing products containing this term you will not know the level of protection afforded by these products, only that it will contain some level of UVA sunscreen. This may vary from country to country, and may depend on their regulations.

You may consider it wise, to purchase your ‘sunscreen’ products before leaving the UK. In this way you can rely on the star rating as your guide. We suggest products containing the five star rating, as these will give the highest level of UVA protection.