Brief Particulars of Recently Introduced Materials likely to have Aircraft, Missile or Space Vehicle Applications. A 16,000‐gallon concrete tank for spent acids has just been lined with ‘Pentaphane’ at the Hatfield plant of the de Havilland Division of Hawker Siddeley Aviation Co. Ltd. This is the first time that ‘Pentaphane’, a chlorinated polyether film manufactured by British Cellophane Ltd., has been used on a concrete tank.