An evaluation of the compatibility between aluminium Finn Chambers and various mercurials dissolved in water or dispersed in petrolatum.

The purpose of the present study was to evaluate compatibility between aluminium Finn Chambers and various mercurials either dissolved in water or dispersed in petrolatum (at the concentrations used in patch test clinics). Aluminium chambers were corroded by aqueous solutions of mercuric oxycyanide, ammoniated mercury and thiomersal, but not by solutions of other mercurials. No corrosion was noted when mercurials had been dispersed in petrolatum, even after 6 months at 37 degrees C. Patch test series of mercurials dispersed in petrolatum were applied on the skin of guinea pigs and in man for 48 h, using aluminium Finn Chambers. No clinical sign of skin irritation was observed. It can be concluded that aluminium Finn Chambers may be safely used for patch testing mercurials if these are dispersed in petrolatum.