Navigating the sunscreen aisle is more challenging than ever. A few key terms:
UVB: Ultraviolet B rays that can burn the skin and are responsible for the majority of skin cancer cases.
UVA: Ultraviolet A rays that can penetrate deeper into the skin and lead to premature aging. A growing number of experts believe they can also be a significant contributor to skin cancer.
SPF: Sun Protection Factor. It measures the relative protection a sunscreen has against sunburn from UVB rays - not UVA. Protective benefits can vary depending on skin type or duration of time in the sun. Higher numbers, such as SPF 30 and SPF 40, are often recommended by health professionals.
Broad spectrum: Sunscreen that protects against both UVB and UVA rays.
Photostability: Sunscreen that retains its protective properties when exposed to sunlight.
Oxybenzone: A common sunscreen ingredient that's come under fire recently for links to endocrine disruption in animals. Experts say no studies on humans have found harmful effects.
Retinyl palmitate: A form of vitamin A that has been shown to accelerate development of skin cancer in mice exposed to sunlight. Experts say the science behind the studies is weak and that similar effects have not been found in humans.