Ammonium persulphate sensitivity in hairdressers.

12 of 49 professional hairdressers patch tested with ammonium persulphate gave positive reactions, in contrast to 1 of 118 patients who were not hairdressers. 7 out of 10 of these 12 patients have since given up hairdressing. The rate of degradation of ammonium persulphate in pet. and in aqueous solution was estimated, and found to be 24% in 6 months.