(1) A head may refuse to grant a request under section 7 if access to the record concerned could, in the opinion of the head, reasonably be expected to -
(a) prejudice or impair -
(i) the prevention, detection or investigation of offences, the apprehension or prosecution of offenders or the effectiveness of lawful methods, systems, plans or procedures employed for the purposes of the matters aforesaid,
(ii) the enforcement of, compliance with or administration of any law,
(iii) lawful methods, systems, plans or procedures for ensuring the safety of the public and the safety or security of persons and property,
(iv) the fairness of criminal proceedings in a court or of civil proceedings in a court or other tribunal,
(v) the security of a penal institution,
(vi) the security of the Central Mental Hospital,
(vii) the security of a building or other structure or a vehicle, ship, boat or aircraft,
(viii) the security of any system of communications, whether internal or external, of the