NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,863 terms related to cancer and medicine.
Browse the dictionary by selecting a letter of the alphabet or by entering a cancer-related word or phrase in the search box.
- A scale for rating the level of sunburn protection in sunscreen products. The higher the SPF, the more sunburn protection it gives. Sunscreens with a value of 2 through 11 give minimal protection against sunburns. Sunscreens with a value of 12 through 29 give moderate protection. SPFs of 30 or higher give high protection against sunburn. Also called sun protection factor.