++++ Free movement of goods - Quantitative restrictions - Measures having equivalent effect - Provision requiring the person responsible for placing a product on the market for the first time to verify its conformity with the rules regarding the health and safety of persons, fair trading and consumer protection - Whether permissible - Conditions - Proportionality of the obligation imposed on importers - Account to be taken of certificates issued by the authorities of the Member State of production ( EEC Treaty, Arts 30 and 36 )