sun protection factor
A person applies sunscreen with a high sun protection factor before going to the beach.
Noun A numerical rating, typically found on sunscreen products, that indicates the degree to which the product protects the skin from the sun's ultraviolet B (UVB) radiation, which is primarily responsible for sunburn. A higher number signifies greater protection and allows for longer sun exposure before burning occurs compared to unprotected skin.
The term "sun protection factor" is used to describe and compare the effectiveness of sunscreen lotions, creams, sprays, and other topical products. It is a standard measurement in dermatology and consumer health.
- Always choose a sunscreen with a high sun protection factor, like SPF 50, for extended outdoor activities.
- The dermatologist explained that the sun protection factor only measures protection against UVB rays, not UVA.
- This bottle claims to have a sun protection factor of 30.
- The term is almost exclusively used in its abbreviated form, SPF. For example: "What SPF is your sunscreen?"
- It is commonly part of compound terms on product labels, such as "SPF moisturizer" or "SPF lip balm."
- SPF: The standard and most common abbreviation for "sun protection factor."
- Broad-spectrum: A related term describing sunscreens that protect against both UVB and UVA radiation. A product can have a high sun protection factor but may not be broad-spectrum.
- Sunscreen: A product that contains agents to protect the skin, characterized by its sun protection factor.
- SPF rating
- Sunblock factor (less common)
The sun protection factor is a multiplier of the time it takes for skin to redden. For instance, if a person's skin normally burns after 10 minutes in the sun, an SPF 30 sunscreen theoretically protects them for 30 times longer (approximately 300 minutes). However, this is a laboratory measure, and real-world effectiveness depends on correct and sufficient application, sweating, and water exposure. It does not indicate the level of protection against UVA rays, which contribute to skin aging and cancer.
A person applies sunscreen with a high sun protection factor before going to the beach.
- the degree to which a sunscreen protects the skin from the direct rays of the sun