The authorisation system is based on the principle of mutual recognition of authorisations. Under this principle, a biocidal product that has already been authorised or registered in one Member State must be authorised in another Member State within 120 days or registered within 60 days of an application being received by the other Member State. However, there are a number of derogations from mutual recognition:

 

The Member State may request that certain conditions relating to the classification, labelling and packaging of biocidal products be adapted under certain circumstances. These involve the quantity of the target species in the territory of the Member State, the degree of resistance of the target organism to the biocidal product and the circumstances under which it is used.

Where a Member State believes that a low-risk biocidal product which has been registered in another Member State does not comply with the definition set out in the Directive it may provisionally refuse to register it. In such cases it must notify the competent authority responsible for verifying the dossier.

Where a Member State believes a biocidal product authorised by another Member State does not meet the conditions for granting the authorisation and proposes to refuse the authorisation or registration it must notify the Commission, the other Member States and the applicant. The case will then be referred to the Standing Committee on Biocidal Products for a final decision which must be unanimously accepted.

Unless otherwise stated in the Treaty, Member States may refuse to grant mutual recognition of authorisations issued for types of products used against vermin, fish and birds, provided that such action is justifiable and does not frustrate the objectives of the Directive.

http://europa.eu/legislation_summaries/internal_market/single_market_for_goods/chemical_products/l21178_en.htm