The mucosal irritant effect of cosmetics and medical products should be thoroughly investigated before market launch. Since 1987, the Draize test on the rabbit's eye, which is controversial among animal rights activists, has been an official test according to the OECD guideline. A suitable alternative is the HET-CAM test on chicken eggs. The substance to be tested is applied to the CAM (chorionic allantois membrane) and the severity of lysis, coagulation and/or haemorrhage is assessed. Since at this stage of development of the chicken embryo the blood vessel system is well formed, but the nerve tissue is not, this test is recognized in Germany as an official pre-test for the Draize test. This ensures that only substances that show a low to moderate mucosal irritant effect in the HET-CAM test are tested on the rabbit. The HET-CAM test thus enables a practical check of the mucosal compatibility of cosmetics, medical products and other chemicals as a suitable screening method.