Article 7
1. Depending on the results of the initial risk assessment, and in order to ensure compliance with the limit value laid down in Article 8, measurement of asbestos fibres in the air at the workplace shall be carried out regularly. 2. Sampling must be representative of the personal exposure of the worker to dust arising from asbestos or materials containing asbestos. 3. Sampling shall be carried out after consultation of the workers and/or their representatives within the undertaking or establishment. 4. Sampling shall be carried out by suitably qualified personnel. The samples taken shall be subsequently analysed, in accordance with paragraph 6, in laboratories equipped for fibre counting. 5. The duration of sampling must be such that representative exposure can be established for an 8-hour reference period (one shift) by means of measurements or time-weighted calculations. 6. Fibre counting shall be carried out wherever possible by phase-contrast microscope (PCM) in accordance with the method recommended in 1997 by the World Health Organization (WHO) ( 7 ) or any other method giving equivalent results. For the purpose of measuring asbestos in the air, as referred to in paragraph 1, only fibres with a length of more than 5 micrometres, a breadth of less than 3 micrometres and a length/breadth ratio greater than 3:1 shall be taken into consideration.