Section 20(2): amended, on 28 October 2021, by section 3 of the Secondary Legislation Act 2021 (2021 No 7).
Section 20(4): substituted, on 19 May 1998, by section 11 of the Copyright (Removal of Prohibition on Parallel Importing) Amendment Act 1998 (1998 No 20).
Section 20(6A): inserted, on 2 July 2001, by section 149 of the Hazardous Substances and New Organisms Act 1996 (1996 No 30).
Section 20(6A): amended, on 1 July 2011, by section 53(1) of the Environmental Protection Authority Act 2011 (2011 No 14).
Section 20(8): inserted, on 28 October 2021, by section 3 of the Secondary Legislation Act 2021 (2021 No 7).