A patient asks a nurse what a sun protection factor (SPF) of 15 indicates. The nurse will tell the patient that an SPF of 15 indicates:

Question

Quizplus · Accepted Answer

A sun protection factor of 15 indicates a 93% block of UVB. As the SPF increases, the increment in protection gets progressively smaller, so an SPF of 15 is not half that of an SPF of 30. Low protection is indicated by an SPF of 2 to 14. The SPF is calculated by the time required for the development of erythema in the protected region divided by the time required for development of erythema in the unprotected region.

A Patient Asks a Nurse What a Sun Protection Factor