reg 9 Measurement of air quality
(1) Having regard to the results of the initial assessment of risk in accordance with regulation 5, in order to ensure that the limit value is not exceeded, the employer must measure regularly the airborne concentration of asbestos fibres in the area of activity. (2) The employer must ensure that sampling carried out in accordance with paragraph (1)— (a) is representative of the exposure of the workers to asbestos, (b) is carried out after consultation with the workers or their representatives, (c) is carried out by suitably qualified personnel, (d) has a duration such that representative exposure can be established for a continuous four-hour reference period by means of measurements or time-weighted calculations, and (e) takes into consideration only fibres with— (i) a length of more than 5 micrometres; (ii) a breadth of less than 3 micrometres, and (iii) a length to breadth ratio greater than 3:1. (3) The employer must ensure that samples taken are analysed in laboratories equipped for fibre counting, which must be carried out wherever possible in accordance with the 1997 WHO recommended method.