Question about Benzoyl Peroxide skin care?

Question

Why do the directions always say to use sunscreen when using benzoyl peroxide-containing products?

Answer 1

You'll be french fried if you don't.

Answer 2

Benzoyl peroxide has the following properties:

Antiseptic i.e. it reduces the number of skin surface bacteria (but it does not cause bacterial resistance and in fact can reduce bacterial resistance if this has arisen from antibiotic therapy). It also reduces the number of yeasts on the skin surface.
Oxidizing agent - this makes it keratolytic and comedolytic i.e. it reduces the number of comedones.
Anti-inflammatory action.