25. Fireglo briquettes, manufactured by Les Combustibles de Normandie at Caen, France, and by La Société Rouennaise de Defumage at Rouen, France, which—
(a)comprise washed Welsh duffs (as to approximately 92% of the total weight) and coal pitch binder (as to the remaining weight);
(b)were manufactured from those constituents by a process involving roll-pressing and heat treatment at about 330°C;
(c)are ovoids which have three lines on one side and are smooth on the other side;
(d)have an average weight of 30 grams per briquette; and
(e)have a sulphur content not exceeding 0.8% of the total weight.