All exits along escape routes have to be designed as emergency exits. Depending on the number of persons who would have to use these emergency exists in the event of danger , these must have a minimum utilisable width of 80 cm. Emergency exists may neither be cluttered, restricted or blocked (by easily tipping objects, for example). It must be possible to use them at any time and they must be unequivocally recognizable as such. Revolving doors are not permissible, and automatic doors are subject to certain restrictions.