6. Bord na Móna Firepak briquettes (also marketed as Arigna Special coal briquettes), manufactured by Bord na Móna Fuels Limited, Newbridge, County Kildare, Republic of Ireland, which—
(a)comprise anthracite (as to approximately 50 per cent of the total weight), petroleum coke (as to 20 to 40 per cent of the total weight), bituminous coal (as to 10 to 30 percent of the total weight) and starch based binder (as to the remaining weight);
(b)were manufactured from those constituents by a process involving roll-pressing and heat treatment;
(c)are unmarked pillow-shaped briquettes and have an average weight of 50 grammes; and
(d)have a sulphur content not exceeding 1.5 per cent of the total weight.