8. Nothing in these regulations shall apply to any scheme or other arrangement or to any regulating instrument in connection therewith—
(a)established for the purposes of or in connection with the Workmen's Compensation Acts, 1925 to 1945, or the enactments repealed by the Workmen's Compensation Act, 1925 , or the Workmen's Compensation Act, 1906 ;
(b)established by a trade union within the meaning of the Trade Union Act, 1913; or
(c)established by the rules of a friendly society, whether registered under the Friendly Societies Act, 1896, or not, if the Minister is satisfied that the number of members of such scheme or other arrangement who were immediately prior to the primary vesting date employed in coal industry activities or transferred allied activities was not a substantial proportion of the total membership of such scheme or other arrangement.