What does SPF stand for?

SPF stands for Sun Protection Factor. This term is crucial in the context of sunscreen and skincare products because it quantifies the level of protection the product provides against ultraviolet (UV) radiation, specifically UVB rays that can cause sunburn and contribute to skin cancer. The number associated with SPF indicates how long a person can stay in the sun without getting sunburned compared to without protection. For example, an SPF of 30 means you can theoretically stay in the sun 30 times longer without burning than if you had no sunscreen on. Understanding SPF is essential for applying sunscreens effectively and ensuring skin safety from sun exposure.

The other choices do not accurately represent the standard terminology used in skincare and sun protection. They either misstate the function of sunscreen or introduce terms that are not commonly recognized within dermatological or cosmetological contexts.