According to the good people at About.com, the sun gives off ultraviolet (UV) radiation that we divide into categories based on the wavelength. UVC radiation is absorbed by the atmosphere and does not cause skin damage. UVB radiation affects the outer layer of skin, the epidermis, and is the primary agent responsible for sunburns. UVB does not penetrate glass, and the intensity of UVB radiation depends on the time of day and the season. UVA radiation penetrates deeper into the skin and works more efficiently. The intensity of UVA radiation is more constant than UVB without the variations during the day and throughout the year. UVA is also not filtered by glass (meaning you’re still exposed to harmful rays when you’re sitting by the window indoors!).
The SPF measures the amount of UVB absorption, but there is no method of reporting the UVA absorption. The only way to determine if a sunscreen protects against UVA and UVB radiation is to look at the ingredients. A good broad-spectrum sunscreen should have an SPF of at least 15 and contain avobenzone, titanium dioxide, or zinc oxide.
Exposure to ultraviolet light, UVA or UVB, from sunlight accounts for 90% of the symptoms of premature skin aging such as wrinkles and skin cancers. The most important skin-care product available to prevent wrinkles and skin cancer is sunscreen, but most people do not use sunscreen correctly.
Okay, all the technical mumbo-jumbo aside, here are a few common mistakes made by many (me included) of us who do use sunscreen.
1. It is not applied soon enough.
You cannot apply it while you are sitting in the full sun watching a football game. For the best protection, you need to apply it 30 minutes before you are exposed to the sun. I see a lot of people doing this at the beach; who only just apply their sunscreen once they hit the beach, and not before.
2. You don’t apply enough.
Your face requires about a teaspoon for the best coverage, while your arms and legs require about a tablespoon. Adjust accordingly for the torso. This is something I’m guilty of, as I often forget to apply sunscreen on my arms and legs as well when I’m out.
3. You don’t by a sunscreen with a high enough SPF factor.
This really becomes important if you aren’t using as much as you should. Too little of a sunscreen with an SPF factor of 15 is reduced to about half or less of that protection factor if you don’t use the suggested amount. For our Malaysian weather, I use SPF50. SPF25 and above would do the trick.
4. You don’t apply it often enough.
One application a day is not enough if you sweat or you are in and out of the water. There are sunscreens formulated for this very purpose, so keep this in mind when you make your next purchase.
So there ya go, some information about the use of sunscreen. I’ll be doing a review of the current sunscreens I’m using in the next few posts to come. I know that a lot of people do not use sunscreens because of the smell (I do admit that I was turned off by a lot of the sunscreens in the market, mainly because of the bad smell), but rest assured that there are some sunscreens out there which do not stink, but smell quite good as a matter of fact.