54. Therma Briquettes, manufactured by Maxibrite Limited at Llantrisant, Rhondda Cynon Taf, which—
(a)comprise anthracite fines (as to approximately 84% of the total weight) petroleum coke (as to approximately 12% of the total weight) and starch binder (as to the remaining weight);
(b)were manufactured from those constituents by a process involving roll-pressing and heat treatment at 250°C;
(c)are oval/tear shaped briquettes with a line through the centre and have an average weight of 26 grams; and
(d)have a sulphur content not exceeding 2% of the total weight.