Dear OncoLink "Ask The Experts,"
Does a t-shirt (long sleeve) block the sun's rays?
Carolyn Vachani RN, MSN, AOCN, OncoLink's Nurse Educator, responds:
Studies on the sun protection offered by summer clothing found that almost half provided less than the equivalent of an SPF of 30. A typical white t-shirt has a sun protection factor around 7, and this drops to about 3 when it is wet. Darker colored clothing and those garments with tighter weave provide more protection. The more worn or stretched out a garment becomes, the less SPF it offers. All of these variables make it difficult for people to assess the protection of clothing, so a system was developed to test and certify the sun protection of fabrics. Read more about clothing with SPF.