Albares appears to be referring to the Copenhagen criteria - so called because they were set out in the conclusions of the 1993 European Council held in Copenhagen.
The European Council today agreed that the associated countries in Central
and Eastern Europe that so desire shall become members of the European Union.
Accession will take place as soon as an associated country is able to assume the
obligations of membership by satisfying the economic and political conditions
Membership requires that the candidate country has achieved stability of
institutions guaranteeing democracy, the rule of law, human rights and respect
for and protection of minorities, the existence of a functioning market economy
as well as the capacity to cope with competitive pressure and market forces
within the Union. Membership presupposes the candidate's ability to take on the
obligations of membership including adherence to the aims of political, economic
and monetary union.
That covers the economic and political conditions - the 'social standards' possibly refer to the ability of the European Union itself to integrate the new member state:
The Union's capacity to absorb new members, while maintaining the momentum
of European integration, is also an important consideration in the general interest
of both the Union and the candidate countries.