Where reasonably practicable, an employer or self-employed person must control exposure to asbestos-
(a) by limiting the number of persons who will be exposed or may be exposed;
(b) by limiting the period during which persons will be exposed or may be exposed;
(c) by limiting the amount of asbestos dust that may contaminate the working environment;
(d) by introducing engineering control measures for the control of exposure to asbestos, which include the following:
(i) process separation or enclosure;
(ii) bonding of asbestos fibres with other materials to prevent the release of asbestos dust; (iii) the use of wet methods, where appropriate; and
(iv) the provision of a negative pressure unit with a filtration efficiency of at least 99 per cent for particles one micrometre in size, in the case of type 3 asbestos work, with a fault indicator to provide early warning of a faillure of the negative pressure unit; and
(e) by complying with the requirements of regulation 19.