What’s the difference- let me keep this basic and get straight to the point- a chemical SPF (sun protecting factor) contains chemicals such as octylcrylen, avobenzone and oxtinoxate. Physicals have natural minerals like zinc and titanium oxide.
How do they differ? – Chemical sunscreens absorb UV rays so our skin doesn’t. Physical sunscreens reflect the rays.
Which is better?
We all know we need SPF to prevent UV rays penetrating our skin and causing cancers or premature ageing but how to choose? The higher the SPF the better right? WRONG!
SPF measures the burn rate of UVB to superficial layers of the skin. However, our collagen is situated in the dermis- the deeper layer of the skin. UVA is able to penetrate to the dermis, so using a SPF with at least 30, containing zinc oxide and titanium oxide will assist in the antiaging process along with looking for an SPF labelled broad spectrum block against UVA and UVB.
It is believed that SPF 15 protects approximately 93% of UV rays, SPF 30 protects against 97% of UV rays. Currently there is no 100% block from UV rays so reapplying a thick layer of sunscreen, wearing hat, glasses and limiting the time exposed to the sun is the best practice.