Approved industry waste management plans under the National Environmental Management: Waste Act 59 of 2008 are instruments of subordinate legislation, not individual administrative decisions. The functus officio principle does not apply to subordinate legislation by virtue of s 10(3) of the Interpretation Act 33 of 1957, which empowers the maker of subordinate legislation to rescind, revoke, amend or vary such legislation. Where an amended plan is identical to the version that underwent public participation save for the removal of an item that was not subjected to that process, no fresh public participation process is required. Section 28 of the Waste Act does not restrict who may submit industry waste management plans - any person may draft and submit such a plan for Ministerial approval. Where portions of subordinate legislation are ultra vires the empowering legislation, those portions may be severed if the good can be separated from the bad, the good is not dependent on the bad, and what remains carries out the main object of the instrument.