Split and simplify the following sentence while retaining its full meaning: Whereas Article 1 of Directive 89/556/EEC excluded embryos derived by certain techniques from the scope of the said Directive; whereas embryos which are to be subjected to techniques which involve the penetration of the zona pellucida and those derived by in vitro fertilization may be introduced into trade or be imported , provided that they meet the requirements of Directive 89/556/EEC , with certain additional safeguards.
 Simplified version:
According to Article 1 of Directive 89/556 / EEC , embryos that have been created using certain processes are excluded from the scope of this Directive . Embryos that are subjected to procedures that involve the penetration of the cell protective layer ( zona pellucida ) , as well as embryos generated by in vitro fertilization , can be traded or imported , provided the requirements of the same directive are met and certain additional guarantees exist .