The act bans the marketing, distribution and sale of smokey coal in Smoke Control Areas. It does not ban the burning of such coal.
In fairness Mary Harney's leglislation of 1990 has been effective in eliminating the smokey coal induced smogs in Dublin and other east coast towns.
Whether it has had any effect on the West Coast Cities and towns is a moot point as the prevailing westerly winds never (or very rarely) allow the thermal inversions which led the the smogs in the east coast.