In this Act—
" accounting year " means any period of twelve months ending with 31st March or the period beginning with the commencement of this Act and ending with the next following 31st March;
" biological substances " means substances whose purity or potency cannot, in the opinion of the Secretary of State, be adequately tested by chemical means;
" the Board " means the National Biological Standards Board;
" the Ministers " means the Secretary of State and the Head of the Department of Health and Social Services for Northern Ireland acting jointly.