3. These Regulations shall not render unlawful anything done before 31st December 1992 in relation to a radiopharmaceutical-associated product if—
(a)products of that description were sold or supplied, or procured to be sold, supplied, manufactured or assembled, at any time before 3rd April 1992; and
(b)products of that description were effectively on the market in the United Kingdom immediately before 3rd April 1992.