27. Inventories
in € thousand  | 
            
  | 
            31.12.2021  | 
            
  | 
            31.12.2020  | 
        
|---|---|---|---|---|
Raw materials, consumables and supplies  | 
            
  | 
            24,185  | 
            
  | 
            22,257  | 
        
Work in progress  | 
            
  | 
            7,978  | 
            
  | 
            2,323  | 
        
Finished products and merchandise  | 
            
  | 
            1,388  | 
            
  | 
            974  | 
        
  | 
            
  | 
            33,551  | 
            
  | 
            25,554  | 
        
Impairment losses on inventories recognised as an expense amount to € 1,091 thousand (previous year: € 1,616 thousand). This expense is reported under cost of materials, see Note 12.