Cookie policy: This site uses cookies (small files stored on your computer) to simplify and improve your experience of this website. Cookies are small text files stored on the device you are using to access this website. For more information please take a look at our terms and conditions. Some parts of the site may not work properly if you choose not to accept cookies.


Subscribe or Register

Existing user? Login

Cancer prevention

Science of sunscreen

Science of sunscreen

Sun exposure is the primary cause of skin cancer. According to Cancer Research UK, more than 8 in 10 cases of melanoma could be prevented through better knowledge of sun damage and how to protect against it.

View the full infographic here

Graph showing differences between UVA and UVB rays and how they can cause DNA mutations

UVA vs UVB radiation, and how they cause skin damage

There are two main types of ultraviolet (UV) radiation:
1) UVB triggers the production of new melanin pigment and stimulates cells to produce a thicker epidermis resulting in a long-lasting tan. It is also the main cause of sunburn.
2) UVA activates melanin pigment already in the skin to produce a short-term tan. UVA penetrates more deeply than UVB and can cause long-term skin damage and premature ageing.

UV light reacts with skin cells to generate free radicals, which can indirectly cause DNA mutations that may lead to the development of skin cancer.

Graph showing differences between chemical and mineral sunscreen

Chemical vs mineral sunscreen

There are two main types of sunscreen available — chemical and mineral. Many new products use a combination of the two.
1) Chemical sunscreens absorb UV radiation and convert it to heat, which is then released from the skin. Common examples include octisalate and avobenzone.
2) Mineral sunscreens act as a screen and reflect and scatter UV radiation in order to protect the skin. Common examples include zinc oxide and titanium oxide.

Table showing different types of sunscreen, their advantages and disadvantages

Types of sunscreen

There are a number of different formulations of sunscreen available and choice will depend on individual requirements.

Illustration showing the important aspects of sunscreen labelling

A closer look at sunscreens

There are several key terms that are used on sunscreen packaging.
1) Water resistant — maintains sunburn protection 40 minutes after water exposure.
2) Once-a-day protection — although some sunscreens claim to provide all day protection, Cancer Research UK and the British Association of Dermatologists advise against relying on any sunscreen for extended periods of time.
3) Broad spectrum protection — protects the skin from both UVA and UVB rays.
4) UVA star system.
5) Sun protection factor (SPF).
6) Expiry date — most sunscreens have a shelf life of between 12 and 18 months after opening. Storing sun cream at high temperatures or in direct sunlight can decrease its shelf life.

Citation: The Pharmaceutical Journal DOI: 10.1211/PJ.2017.20203013

Have your say

For commenting, please login or register as a user and agree to our Community Guidelines. You will be re-directed back to this page where you will have the ability to comment.

Recommended from Pharmaceutical Press

  • Print
  • Share
  • Comment
  • Save
  • Print Friendly Version of this pagePrint Get a PDF version of this webpagePDF

Supplementary information

Newsletter Sign-up

Want to keep up with the latest news, comment and CPD articles in pharmacy and science? Subscribe to our free alerts.