50. HouseFuel Smokeless Ovals, manufactured by Maxibrite Limited at Mwyndy Industrial Estate, Llantrisant, Rhondda Cynon Taf, which—
(a)comprise bituminous coal and petroleum coke (each as to approximately 10 to 15% of the total weight) and anthracite duff and starch binder (as to the remaining weight);
(b)were manufactured from those constituents by a process involving roll-pressing and heat treatment at about 260°C;
(c)are unmarked pillow-shaped briquettes with approximate maximum dimensions 68 millimetres, 63 millimetres and 38 millimetres;
(d)have an average weight of 110 grams; and
(e)have a sulphur content not exceeding 1.9% on a dry basis.