Sun Protection Tips

David F. Jaffe, MD, PA
323 S Union Avenue
Havre de Grace, MD 21078


Dear Patient,

There are many things said about sunscreens that are not true and many things that should be said about sunscreens that you will not hear from other places. This page is to inform you of some important details.

Sunscreens do not last very long on the skin in hot weather. This explains why many people who are sure they have applied sunscreen when they are at the beach get burnt anyway. Current research seems to indicate that sunscreens need to be applied approximately every 30 to 45 minutes in the heat. This is especially true if you are going in and out of water or using a towel.

The SPF number on a sunscreen is NOT the sun protective value that you are going to get when you use a sunscreen. This is because the thickness of the sunscreen application to perform the test that determines the SPF number is such a thick application that you would be uncomfortable if you attempted to apply the sunscreen in this way. Consequently, the old rule that an SPF of 15 is adequate is simply not true because you are not applying the sunscreen thickly enough to trulyy get this level of protection. Therefore, we recommend that you buy sunscreens with an SPF no less than 30 in order to end up with a functional SPF of about 15.

The sunscreens that have been created up until now have afforded protection mostly against the common skin cancers -- basal cell and squamous cell carcinoma -- in addition to prevention of sunburn. Because they do not have wide wavelength blocking capability they have not been effective in reducing the risk of melanomas. This year, there are new sunscreens out that have begun to actually protect against a wider wavelength spectrum and thus give better protection. We are recommending that sunscreens should have one of the following ingredients in them:

1. Avobenzone
2. Parson 1789
3. Zinc oxide

If your sunscreen does not have one of these ingredients in it, we would encourage you to purchase one that does.

David F. Jaffe MD
Diane Williams, PA-C