7. For the purposes of paragraph 4(d) and 6(1)(c), biomaterial is added to a fuel for an exempt purpose if—
(a)it is added to the fuel—
(i)to act as a binding agent, or
(ii)to reduce the emissions of dust, carbon dioxide, methane or nitrous oxide from the use of the fuel, and
(b)it does not exceed 2% by weight of the fuel.