What SPF is most recommended and approximately what percentage of blocking does it provide?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $25.99Unlock all

Study for the History and Physical (Handamp;P) Exam 1. Prepare with flashcards and multiple choice questions, each question has hints and explanations. Get ready for your exam!

Multiple Choice

What SPF is most recommended and approximately what percentage of blocking does it provide?

Explanation:
Blocking of UVB increases with higher SPF, but the gains get smaller as SPF rises. In practical terms, the fraction of UVB blocked is about 1 minus 1 divided by the SPF, so SPF 50 blocks roughly 98% of UVB, SPF 30 about 97%, SPF 20 about 95%, and SPF 15 about 93%. Among common options, the highest SPF provides the most protection, so SPF 50 with about 98% blocked is the best choice. Remember to use a broad‑spectrum product to cover UVA as well, and reapply every two hours or after swimming or sweating.

Blocking of UVB increases with higher SPF, but the gains get smaller as SPF rises. In practical terms, the fraction of UVB blocked is about 1 minus 1 divided by the SPF, so SPF 50 blocks roughly 98% of UVB, SPF 30 about 97%, SPF 20 about 95%, and SPF 15 about 93%. Among common options, the highest SPF provides the most protection, so SPF 50 with about 98% blocked is the best choice. Remember to use a broad‑spectrum product to cover UVA as well, and reapply every two hours or after swimming or sweating.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy