Issue link: https://www.ascpskindeepdigital.com/i/70637
Chemical or Physical? The UV radiation in sunlight consists of UV-A, UV-B, and UV-C rays. UV-A and UV-B are both responsible for photoaging, skin cancer, sunburn, tanning, and wrinkling. UV-C is not a factor in skin health, as it is absorbed by the Earth's atmosphere and does not reach us in significant amounts. Broad-spectrum sunscreen protects against both UV-A and UV-B. This protection can work in one of two ways: chemical or physical. CHEMICAL UV FILTERS • Work by absorbing UV radiation. • Require application 30 minutes before sun exposure. • Provide partial protection from UV spectrum. • May irritate the skin and eyes. • Not regulated for safety by the FDA; some may even be carcinogenic. • Not photostable (exposure to sunlight degrades effectiveness). • Avobenzone is the most commonly used chemical filter ingredient. PHYSICAL UV FILTERS • Work by reflecting UV radiation. • Start protecting immediately upon use. • Provide full broad-spectrum protection. • Non-irritating to skin and eyes. • Safe, as particles do not penetrate the skin. • Highly photostable (exposure to sunlight does not change effectiveness). • Zinc oxide and titanium dioxide are the most commonly used physical filter in- gredients. Clothing and shade structures also count as physical filters. Sunscreen Timeline A recipe for homemade sunscreen is published in The Lady, an English women's magazine: calamine, oxide of zinc, spirits of ether, glycerin, and rose water. Franz Greiter creates the Sun Protection Factor (SPF) sunscreen rating system. FDA publishes proposed sunscreen regulations. FDA issues a nonbinding Final Monograph on sunscreen regulations. FDA indefinitely stays the effective date of the 1999 Final Rule. FDA publishes proposed sunscreen regulations, which include UV-A testing methods and labeling requirements. 1926 1946 1962 1978 1993 1997 1999 2000 2001 2004 2007 2011 FDA The first mass- produced sunscreens are sold. Originally used by the US military in World War II, they were fairly ineffective and provided minimal UV protection. 32 ASCP Skin Deep July/August 2012 FDA begins to develop sunscreen regulations. Congress mandates that the FDA provide binding regulations for over- the-counter sunscreens within 18 months. FDA extends effective date of the 1999 Final Rule to 2002. FDA "delays until further notice" the implementation date for the 1999 Final Rule. publishes new Final Rule, which includes UV-A testing methods and labeling requirements, to be effective June 18, 2012.