Introduction: Until recently, the determination of the reduction in work capacity (MdE) in cases coming under the occupational disease number (BK-Nr.) 5102 BKV has not been carried out consistently. Now modifications have been made to the MdE recommendations published in 1993 with the view of making them more consistent in practical use. Since 01. 11. 2004, the Statutory Accident Insurance in the Chemical Industry Cologne has been implementing these recommendations consistently. Between 01. 11. 2004 and 25. 4. 2006, 55 insured individuals with an occupational disease recognized as BK-Nr. 5102 were re-examined and their MdE levels checked. Materials and Methods: Occupational disease records served as the basis for obtaining standardized data. The data recorded on a standardized evaluation form included information on localisation and histological findings for skin tumours, the year in which the disease appeared and was initially appraised, and the levels of the MdE recommendations before and after the 01. 11. 2004. Results: The insured individuals were between 46 and 93 years of age. The length of time worked at the company was between 7.7 and 47.2 years. The number of basal cell carcinomas diagnosed in each case was between n = 1 and n =18 and the number of squamous cell carcinomas between n = 1 and n = 5. The MdE recommendations for 35 insured individuals were changed and for 20 individuals not changed. Because changed MdE levels can also be due to changes in the condition of the skin between the two examinations, it is necessary to carry out a differentiated examination of each individual case. 73.5 % of the doctors carrying out the examinations advised yearly follow-up examinations, the rest advised that an examination be carried out every two years. Only in the case of two insured individuals were sensitivity to sunlight and cosmetic adjustment mentioned in the doctors‘ reports. Conclusions: Regular quality checks within the framework of quality control would be likely to help evaluate further still-existing discrepancies in appraisal practice.