title: Ultraviolet A sunscreen evaluations in normal subjects.
abstract: We have used a specially modified xenon arc solar simulator to examine ultraviolet A (UVA) protection of a research sunscreen formulation. UVA doses were given to sunscreen-protected and unprotected skin with the use of irradiance values of 50 mW/cm2 and 100 mW/cm2. Erythemal responses were evaluated 5.2 +/- 0.9 hours later and again 24.4 +/- 1.8 hours later. The overall mean unprotected UVA minimal erythema dose (MED) was 23.6 joules/cm2 (SD = 4.8) and the mean UVA protection factor (APF) was 3.2 (SD = 0.78). Neither irradiance nor evaluation time significantly affected MED or APF. These preliminary findings indicate that the modified solar simulator permits convenient determination of sunscreen APF. The APF of a sunscreen is analogous to SPF: APF refers to UVA protection, while SPF refers to protection from the entire solar spectrum, predominantly from the effects of UVB.
authors.affiliation: Bristol-Myers Pharmaceutical Research & Development, Buffalo, NY 14213.
authors.forename: J W
authors.initials: JW
authors.lastname: Stanfield
authors.forename: P A
authors.initials: PA
authors.lastname: Feldt
authors.forename: E S
authors.initials: ES
authors.lastname: Csortan
authors.forename: L
authors.initials: L
authors.lastname: Krochmal
mesh_terms: D000328:Adult; D000512:Alpha Particles; D004890:Erythema / Q000209:etiology / Q000517:prevention & control; D005260:Female; D006801:Humans; D008297:Male; D012867:Skin / Q000528:radiation effects*; D013473:Sunscreening Agents / Q000592:standards*; D013997:Time Factors; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D013473:Sunscreening Agents