This document provides information on sunscreen ingredients and formulation. It discusses the electromagnetic spectrum and how different wavelengths of UV radiation interact with skin components. It describes the sun protection factor (SPF) rating system and covers common active ingredients used in sunscreens like organic UV filters (octinoxate, avobenzone), physical blockers (zinc oxide, titanium dioxide), and how they provide protection across the UVA and UVB ranges. The document also addresses formulations, skin types, and myths regarding sunscreen use.