2. GENERAL INFORMATION ON TENDERING  2.1 Legal basis: what are the rules?  2.2 Rules on access to procurement: who may submit a tender?  The present call for tenders is governed by the Financial Regulation of the European  Chemicals Agency (ECHA), which refers to the provisions of Regulation (EU, Euratom)  2018/1046 of the European Parliament and of the Council of 18 July 2018 on the financial  rules applicable to the general budget of the Union (the Financial Regulation) 4 .  The  Contracting Authority  has chosen to award the FWC resulting from this call for tenders  through an open procedure pursuant to Article 164(1) (a) of the Financial Regulation. In an  open procedure any interested economic operator (any natural or legal person who offers the  relevant services, and that has access to the procurement in accordance with  section 2.2 ),  may submit a tender.  Participation in this call for tenders is open on equal terms to all natural and legal persons  coming within the scope of the Treaties, as well as to international organizations. It is also open to all natural and legal persons established in a third country which has a  special agreement with the European Union in the field of public procurement on the  conditions laid down in that agreement. This procedure is, however, not covered by the  Government Procurement Agreement (GPA).    For tenderers established in the United Kingdom: Please be aware that following the entry into force of the EU-UK Withdrawal Agreement 5  on  1 February 2020 and in particular Articles 127(6), 137 and 138, the references to natural or  legal persons residing or established in a Member State of the European Union are to be  understood as including natural or legal persons residing or established in the United  Kingdom. UK residents and entities are therefore eligible to participate under this call for  tenders until the end of the transition period established by the EU-UK Withdrawal Agreement  (i.e. 31 December 2020). Following the end of the transition period, UK residents and entities  will be considered natural and legal persons established in a third country. In this regard,  tenderers shall be aware of the minimum requirements defined in section I.4.2 if relying on  other entities established in UK.  ECHA may terminate the framework contract, or specific contracts signed therein, with UK  economic operators, based on the provisions of the framework contract; when the given  4  Regulation (EU, Euratom) 2018/1046 of the European Parliament and of the Council of 18 July 2018 on the  financial rules applicable to the general budget of the Union, amending Regulations (EU) No 1296/2013, (EU) No  1301/2013, (EU) No 1303/2013, (EU) No 1304/2013, (EU) No 1309/2013, (EU) No 1316/2013, (EU) No  223/2014, (EU) No 283/2014, and Decision No 541/2014/EU and repealing Regulation (EU, Euratom) No  966/2012 (OJ L 193 of 30.07.2018, p.1).  5  Agreement on the withdrawal of the United Kingdom of Great Britain and Northern Ireland from the European Union  and the European Atomic Energy Community 11