6. Functional costs

Cost of sales

The cost of sales mainly relates to the cost of materials and other purchased manufacturing services, gains and losses from changes in the fair value of biological assets, personnel expenses, depreciation and amortization and other operating expenses, in particular expenses for maintenance and repair, other third-party services and expenses for waste disposal. The expenses for maintenance and repair amount to EUR 71,223 thousand (2023: EUR 63,187 thousand) and for maintenance material and cleaning to EUR 109,484 thousand (2023: EUR 113,942 thousand).

Selling expenses

Selling expenses mainly relate to personnel expenses and other operating expenses, particularly expenses for outbound freight as well as rental and leasing expenses.

Administrative expenses

Administrative expenses mainly relate to personnel expenses and other operating expenses, in particular legal, audit and consulting expenses.

Research and development expenses

Research and development expenses mainly relate to personnel expenses and other operating expenses, in particular filing and defense costs for patents and trademarks. Research and development expenses include amortization of intangible assets, depreciation of property, plant and equipment and right-of-use assets, and depletion of biological assets amounting to EUR 1,639 thousand (2023: EUR 53,482 thousand) and income from the release of investment grants amounting to EUR 143 thousand (2023: EUR 140 thousand).