9. Any occupation involving—
(a)the working or handling of asbestos or any admixture of asbestos;
(b)the manufacture or repair of asbestos textiles or other articles containing or composed of asbestos;
(c)the cleaning of any machinery or plant used in any of the operations in the preceding two paragraphs, and of any chambers, fixtures and appliances for the collection of asbestos dust;
(d)substantial exposure to the dust arising from any of the operations in sub-paragraphs (a) to (c).