2. Section 141A(1) of the Criminal Justice Act 1988 (sale of knives or certain articles with blade or point to persons under sixteen) shall not apply to —
(a)a folding pocket-knife if the cutting edge of its blade does not exceed 7.62 centimetres (3 inches).
(b)razor blades permanently enclosed in a cartridge or housing where less than 2 millimetres of any blade is exposed beyond the plane which intersects the highest point of the surfaces preceding and following such blades.