The influence of temperature on the concentration homogeneity of patch test materials

The concentration homogeneity of Dieted sulphate 4.8%. pet, and potassium dichromate 0.5% pet. in patch test materials appeared to become less homogeneous if stored at room temperature compared storage al 4°C. after 2 months, The coefficient of variation of concentration for nickel sulphate alter storage at 4°C W;LS 3.0883%, and at room temperature 25.3098%. The coefficient of variation for potassium dichromate after storage at 4°C was 4.6124% and at room temperature 9.6334%. This indicates that patch less materials containing nickel sulphate and potassium dichromate should be Kepi refrigerated in the tropics.