[Evaluation of the chorioallantoic membrane in the chick embryo to test the irritation potential of chemical and cosmetic products].

A large number of new chemicals and cosmetics are introduced every year and it is necessary to find a reliable method for the detection of potential irritants. Hitherto used, for this purpose, in vivo rabbit eye test (Draize's test) should be substituted by alternatives because of ethical and legal aspects. One of the most promising method predicting the irritant potential is test performed on the chorioallantoic membrane of the chick embryo (CAM-test) [5]. This membrane is a complete tissue including arteries, capillaries and veins and is technically easy to study. The aim of the study was to check reliability and sensitivity of the test. The principles of the method are simple. The test substance (pure, dissolved or suspended) is applied to the CAM at a volume of 200 microliters. The blood vessels and the remaining parts of the membrane are examined and scored for irritant effects (hyperaemia, lysis or coagulation) after 0.5, 2 and 5 minutes treatment. The numerical, time-dependent score (Table III) are summed to give a single numerical value indicating the irritation potential of the tested substance (Table II). The final assessment is based on the mean value from four experiments. A summary of the results of CAM irritation testing of some of chemicals and cosmetics is given in Tables IV, V and VI. Table VII shows results of assessment of irritation potential of various cosmetics tested by two methods: CAM and Draize eye tests. It was found that CAM test is a rapid and very sensitive method which can give an information on the potential of irritation of chemical substances and cosmetics.