Define UV-A and UV-B
A good sunscreen offers broad spectrum protection against UV-A and UV-B rays. UV-A rays cause premature ageing of the skin whereas UV-B rays cause sunburn. In the past, UV-B rays were regarded as the main cause of skin cancer. However‚ the University of Sydney have shown that UV-A radiation plays a large role in causing gene mutations that can lead to skin cancer. Therefore it is vital that when using a sunscreen you check that if offers broad-spectrum protection.
SPF stands for Sun Protection Factor. SPF numbers are an approximate indication of how much protection from the sun a product will provide for your skin. For an average person skin starts to burn after 10 minutes in the sun. A sunscreen with SPF 30 means protection is offered for upto 300 minutes or 5 hours before skin will start to burn. An SPF 15 sunscreen offers 150 minutes or 2.5 hours of protection before burning. So it makes sense to always buy an SPF30 sunscreen.
Danger of Chemical UV Absorbers
Chemical UV-absorbers are absorbed very easily into the body and into the bloodstream. When exposed to sunlight these chemicals produce harmful free radicals that have the potential to damage cells and destroy DNA.
Excipients make up approximately 80 per cent of sunscreens and act as the carriers or base materials of a product. They “receive” and carry the other ingredients. Excipients include mineral oil‚ petrolatum‚ isopropyl esters‚ lanolin derivatives, aliphatic alcohols, emulsifiers, fragrances, thickeners and preservatives. In Australia‚ sunscreen manufacturers only have to list the “active ingredients‚” those that are used in blocking the sun, and preservatives. So what not on the label could be harming you.
When looking for a safe sunscreen choose one that acts as a barrier. A barrier sunscreen is on that sits on the surface of the skin and creates a barrier between the UV rays and the skin. Zinc Oxide is considered the safest barrier ingredient and offers broadspectrum protection.
Choose a sunscreen that lists all the ingredients. This list should be at least 10 items long and be mostly plant based oils.
While I was doing my research for this article I came across this environmental guide to Sunscreens at www.ewg.org/2014sunscreen. On this website it provides a comprehensive, by all means not complete, list of sunscreens and their overall safety.