RT Journal Article SR Electronic T1 Topical sunscreens JF Drug and Therapeutics Bulletin JO Drug Ther Bull FD BMJ Publishing Group Ltd SP 61 OP 63 DO 10.1136/dtb.28.16.61 VO 28 IS 16 YR 1990 UL http://dtb.bmj.com/content/28/16/61.abstract AB Ultraviolet (UV) radiation reaching the earth consists of UVB (wavelengths 290–320 nanometres) and UVA (320–400nm). UVC (100–290nm) is still stopped by the ozone layer. UVB causes sunburn, but both UVB and UVA cause skin cancer and skin ageing. Severe sunburn may be a risk factor for melanoma.1 Numerous sunscreens are used to prevent sunburn or to protect patients with photodermatoses; which ones should be recommended?