A tax which is charged on aggregate when it is subjected to commercial exploitation in Scotland is a devolved tax.
The tax must not be chargeable when aggregate is subjected to commercial exploitation for fuel.
Aggregate is subjected to commercial exploitation for fuel—
when the aggregate is used as fuel;
when the aggregate is subjected to commercial exploitation for the purpose of extracting or producing anything capable of being used as fuel;
when the aggregate becomes subject to an agreement to use it as mentioned in paragraph (a) or to subject it to commercial exploitation as mentioned in paragraph (b).