Property, plant and equipment
Plant and equipment is stated at cost, net of accumulated depreciation and/or accumulated impairment losses, if any. Repair and maintenance costs are recognised in the income statement as incurred.
Depreciation is calculated on a straight-line basis over the estimated useful life of the asset as follows:
| • | Land and buildings: 15 to 20 years |
| • | Plant and equipment: 5 to 15 years |
| • | Laboratory equipment: 3 to 5 years |
| • | Office furniture: 3 to 10 years |
| • | Leasehold improvements: 3 to 10 years (based on duration of office building lease) |
An item of property, plant and equipment and any significant part initially recognised is derecognised upon disposal or when no future economic benefits are expected from its use or disposal. Any gain or loss arising on derecognition of the asset (calculated as the difference between the net disposal proceeds and the carrying amount of the asset) is included in the income statement when the asset is derecognised.
The assets’ residual values, useful lives and methods of depreciation are reviewed at each financial year end, and adjusted prospectively, if applicable.