IMO it depends on your skin type, lifestyle, local climate, indoor or outdoor job/ hobbies, shiftwork or 9-5, drive/ cycle/ walk/ use public transport, beach holidays or ski-ing ... official guidelines are about avoiding skin cancers, not so much the chronic low levels of UV that contributes to ageing, so skincare companies may offer different products to each group.
"Another way to look at it is in terms of percentages: SPF 15 blocks approximately 93 percent of all incoming UVB rays. SPF 30 blocks 97 percent; and SPF 50 blocks 98 percent. They may seem like negligible differences, but if you are light-sensitive, or have a history of skin cancer, those extra percentages will make a difference. And as you can see, no sunscreen can block all UV rays. ....
What type of sunscreen should I use?
The answer depends on how much sun exposure you're anticipating. In all cases we recommend a broad-spectrum sunscreen offering protection against both UVA and UVB rays. Many after-shave lotions and moisturizers have a sunscreen (usually SPF 15 or greater) already in them, and this is sufficient for everyday activities with a few minutes here and there in the sun."
BTW Devita offer the Rx Ultrasolar 50 which contains 8% titanium dioxide and 19% zinc oxide. Their Body Block 30 and the Solar Protective 30 are both 19% zinc according to the Essentialdayspa store.
Originally Posted by Monocled Penguin
BTW: Is it really OK for all these brands (Devita, Osmosis, etc) to offer ZnO sunscreens at such low percentages; 13.5%, 14%, etc? Or are you guys reapplying more often?