The UKIPO has recently published a list of technologies which it considers to be either military or prejudicial to national security or public safety.  Patent applications for any such technologies may be placed under directions restricting their disclosure under section 22 of the Patents Act 1977.  Further, permission must be obtained from the UKIPO before filing any patent application abroad which relates to inventions concerning the listed technologies.

Every application (whether a UK national application, a European application or a PCT application) filed at the UKIPO is screened to check whether it should be placed under directions under section 22 of the Act.  An applicant is notified within 6 weeks from filing the application if such restrictions are to be imposed.  If the application is a UK national application, then the restrictions may prevent discussion of the contents of the application with any person without permission and the filing of the application abroad.  European and PCT applications which are filed at the UKIPO and placed under section 22 restrictions will not be forwarded to the EPO or the International Bureau, respectively.  The directions under section 22 may only be lifted once the application has been inspected by the Ministry of Defence, which is usually 18 months after the initial priority date, although early inspection can be requested.

The list of technologies discussed above is quite extensive and not only encompasses technologies which are clearly prejudicial to public safety e.g. nuclear weapons or explosives, but also technologies which may not obviously fall within this category e.g. various alloys, catalysts for hydrogen peroxide breakdown, methods for detecting toxins, to mention a few.  The published list of technologies can be seen at http://www.ipo.gov.uk/types/patent/p-applying/p-after/p-security/p-security-guidance.htm