SAN DIEGO — No matter what sun protection factor sunscreen you recommend, remember that the SPF system has its limitations, Shanna Meads, M.D., advised at a melanoma update sponsored by the Scripps Clinic.
For one thing, SPF measures only UVB protection, not protection from UVA rays, said Dr. Meads, a dermatologist and Mohs fellow at the Scripps Clinic-Torrey Pines, La Jolla, Calif.
Also, SPF is measured and classified under controlled laboratory conditions, “and most people don't live in a laboratory setting,” she said.
And finally, consumers must follow directions for proper sunscreen use. “You have to apply at least 30 g to cover the entire body,” she said. “You have to apply it 20 minutes prior to sun exposure and reapply every 60-90 minutes. Most people don't follow these directions and may never achieve the SPF that's been achieved in a laboratory setting.”
She recommended the following products to use in conjunction with proper sunscreen application:
▸Sun protective clothing. UV protection factor (UPF), a rating similar to SPF, measures the efficacy of these clothes. Factors increasing UV protection in these products include tighter weave, dark color, heavier fabric, and less stretch. These clothes are generally are made of wool, polyester, and/or acrylic, and can be expensive.
▸Laundry. Sun Guard, manufactured by Rit, contains Tinosorb, a fabric brightener that penetrates fabric fibers and blocks UV rays. Patients can add it to their regular wash load. The maker says it provides protection for 20 washings.