Various occupational substances may cause dermatological lesions. Toxic, toxic-degenerative and allergic eczemas have to be mentioned on the first hand. The prevention of dermatoses ranges among the most important tasks of occupational medicine. The first measure should be a minimization of the direct skin contact with dermatotoxic substances. Here, adequate cleaning products play an important part. --When working with potentially toxic substances, the use of protective devices must be recommended. There are two possibilities: wearing gloves or application of protective ointments. In both instances, numerous disadvantages have to be considered. The main point is the reduced quality of work. Recently, a foam product for external protection has been developed. Clinical experiments and first practical experiences permit the assumption that this foam product which forms a biphasic lattice in the outer layers of the stratum corneum may ameliorate the situation.