Question: How do I choose a good sunscreen?
The Makings of a Good Sunscreen:
In terms of sunscreen, there are two main categories: physical vs. chemical types. For those with sensitive skin, a physical sunscreen (those containing zinc or titanium as active ingredients) may be preferable to products with chemical sunscreens as the active ingredients, as the physical sunscreens are less likely to cause allergies and are also more effective.
It is also important to know that there are different types of UV radiation and that different types of UV rays can be damaging in different ways. Both UVA and UVB rays are associated with skin cancer, however UVB rays are more carcinogenic while UVA rays are more associated with the sun damage that causes aging of the skin. A good sunscreen should block both UVA and UVB rays, and thus in reading sunscreen labels, one should look for words like “Broad Spectrum” and “UVA/UVB protection.” Products that contain zinc or titanium as active ingredients tend to do a good job of blocking a broad spectrum of UV Rays.
If one is going to be at the beach or the pool, or sweating a lot outdoors, it may also to be useful to find products that are also water resistant.
How High of an SPF do I need?
For daily use one should use a sunscreen that has at least SPF 30, although SPF > 50 is better for more fair skin types and for those who have had skin cancer in the past, and also if more intense sun exposure is anticipated, for example at the beach or at high altitudes (e.g. skiing).
Patients often ask if higher SPF’s really make a difference. The answer is that the differences become smaller as SPF goes up, however differences do still exist. For example, it is true that the greatest difference in sun protective effect is that between wearing no sunscreen at all and wearing a sunscreen with SPF 15. The difference in sun protection between SPF 15 and SPF 30, and then between SPF 30 and SPF 50 is less however still can make a difference for a person.
To help illustrate this concept, I have created a very rough graph (not drawn to scale) for reference here:
These smaller difference in UV protection afforded by higher SPF sunscreens become more and more important if a person is going to be in a situation involving high UV exposure for example: at the beach, at high altitude (e.g. skiing, hiking in the mountains, etc) or outdoors in the summertime especially during peak hours of sun exposure (10 am – 4 pm).
“An Ounce of Prevention.”
For most adults, 1 ounce of sunscreen (i.e. the amount that would fill a shot glass) is the proper amount to cover the face, and other areas exposed to the sun. However it is also important to remember that to really be effective, it is necessary to reapply sunscreen about every 2 hours.
Even with the best sunscreen available, there is no substitute for a physical block from the sun such as being in the shade or wearing a broad brimmed hat. There are hats available with UPF (Ultraviolet Protection Factor – sun protective fabric that is the clothing equivalent of sunscreen). Hats and clothing with UPF can be ordered online and found in sporting and swimwear shops.
Here is a Sunscreen Checklist:
* High SPF (50 or above)
* Broad spectrum (Blocking both UVA and UVB rays)
* Water resistant
* Physical Sunscreen (containing zinc or titanium as active ingredients)
* Remember to reapply every 2-3 hours.
* Wear sun protecting hats and clothing that contain Ultraviolet Protection Factor (UPF)
Also remember to avoid sun exposure during times of day when UV exposure is at its highest intensity (10 am – 4 pm).
Best wishes for a health and happy summer!